Since you mentioned in your post that you plan to hold for a long term it means; the funds that you’ve invested won’t be needed anytime soon and if that’s true I’ll suggest you stick to it and look for other means to generate funds to support those businesses that you want to support.

Your investment funds should be different from those you plan to use for charity works. Or except you plan to get some kind of reward from helping them I’ll suggest you look for other means  to generate money like I mentioned.  And as we normally say in my local language “Nor go put hand for Watin your power nor fit carry”

I agree with Zaguru12, I think you should invest in expanding your business. I’m a strong believer of hodling but also understand the importance of having a business with constant cashflow. With cashflow, you can buy more bitcoins from the profits you make from the business.
You didn’t tell us the business you’re into, only that you accept bitcoin as payment. In this case, I don’t think it matters whether or not your business accepts bitcoin. The important thing is the product or service you’re selling and how profitable the business is.

IMHO, there's no need to get confused by having your long term holding plan focused as what it is and also by simply supporting a business that accepts Bitcoin. Think of what is important to you now? Holding can be done with other activities that's going to make you productive. What are you thinking then? having to slash some BTC holdings for you to support that business? If you don't have any other money from other sources that you have and you're thinking of helping that business through taking a part of your holdings to support it, don't take all of it. There's more to business and you shouldn't put full force of your assets or resource on it as you start. There's a period that you need to study on it during the operation before you fully expand or see if it's worth it to continue it.

It means you don't have spare funds not because you have to choose between maintaining or supporting the business you want to run even if it starts adopting bitcoin in bitcoin acceptance.

If there is only this second choice then you need to carefully consider whether your new business by adopting will go according to plan going forward? And see what you think the business income is if it is possible for you then support your business.

Another way maybe if your portfolio is already large try to take some capital from what you keep the BTC, the rest you can accumulate again from the results of your business profits into the portfolio, but if you take everything that has been invested in BTC then just to support your business then I think it's very unfortunate especially soon BTC will halving will trigger a higher increase.

This is a personal opinion but you can consider other things that you think are relevant and in line.

Your intention is to support the Bitcoin-Network in any way that you can. Holding is also part of the support, in my opinion, and accepting Bitcoin in your business is also part of the support. Supporting businesses that accept Bitcoin by patronising them is also another means of showing support. What matters is, that there is a transaction going on in the network; there's enough support for it.
 
It is important to think carefully before making any decisions, whether personal or business-related. When it comes to your business, make sure that you are not blinded by your love for blockchain technology and are not taking unnecessary risks. Remember to stay focused on your goals and make sound decisions that will help you achieve success.
 
If you run out of business and there is no longer a stable cashflow, your holding life won't be strong again, as a strong holder is backed up by a stable inflow of income, which will be enough to foot bills, and the need for the holding to be spent won't be there.

Just to point out that there are other ways you can support a business that is accepting Bitcoin besides paying for a product in Bitcoin, especially if you're not going to do that consistently. You can;
• Promote their business to their target audience,
• Offer advice to them to help them better use Bitcoin as a payment method,
• Buy their product in other currencies on offer that you are comfortable spending. Most businesses convert the bitcoins instantly to fiat, so paying in fiat is also a financial support to the business.

These are options you can go for if liquidating some of your bitcoins is too much of a leap to take and it will still give you results.

I don't know how you intend to support the business but there will always be opportunities to contribute to the Bitcoin ecosystem. If the business will not collapse because of your failure to invest or patronise them, I suggest that you keep holding and support the business after you have sold your coin and made some profit. Like others have said there are also diverse means of supporting the business than liquidating your investment. Introduce the business bitcoiners and you can also convert your spare cash to bitcoin and patronise them. You could offer other services like training staff on how to process bitcoin payments and you can even expose them to the Lightning Network and how to protect wallets. I don't think anything should prevent you from following your investment plans except for emergencies. But if you think assisting the business will give you much joy and satisfaction you can go on and sell your coins to support them, after all, everything is not money. But I must also compliment you for considering contributing to the Bitcoinspace above maximizing profit.    

The OP didn't say the business belongs to him. I think he wants to support a business with no intention of making a profit. His main goal is to contribute to the expansion of a business that accepts Bitcoin in his locality.  

Find the balance by accepting that you are fulfilling the purpose of bitcoins, and try to readjust your plans to fit in both options.

 It will not hurt to spend some few bitcoins on some little things once in a while. You will never find balance in your heart if your plan for bitcoin remains to hodl 100%, you have to find and create some allocation for it in percentage in your plan, not just 100% for Hodling, and then 0% for use as currency.

You may strike a balance by planning for both of them, and they will both work.

Normally, if you want to support a business, you will set aside some money for that purpose. In this case, it will be the same as supporting your business and contributing to Bitcoin adoption in your community; and your bitcoin holding will continue in the same manner as before, because it is clear that money for other businesses is not added to our bitcoin investment because it is for the long term.