Now I am profiting from my Bitcoin investments then and one of my colleagues is now in dear need of financial help, he needs some help, not life-threatening but money, and now I am not ready to loan him any money as long as it affects my overall Bitcoin holdings.
You know the answer bud. You have to say NO because these friends of ours are just using us as an option even if they have another greater option. You have admitted that you're not ready to loan him and you have taken your want away instead of taking them close to you with that money of yours. You've sacrificed for how long and then there's this guy will approach you out of nowhere trying to loan you some money. Just say politely that you're not going to lend him some money or if you can give him a little portion of your spare money that you're okay in not getting paid with it so you just can get rid of him trying to ask you once in a while. I've been there and done that, they're quick to ask money but when you ask them to pay money, they're turning into dust and gone in the wind.

agree with you, if the OP doesn't actually want to lend the money. it's better to say firmly that you can't give him a loan. You could say your money is being invested, so you can't give it away quickly and it will take a long time to withdraw it.
but if you still have a sense of humanity, you can just buy their goods. That way they are still helped financially, you can still have what they bought before. or just give away a small portion of your profits. It's time to share your good fortune with those who need it more.