Thanks But No Thanks

It drives me crazy when people can't seem to accept a gift and just say thank you.
See, I'm broke. I have been for a long time and that's fine. I get by and I'm not starving or anything, so whatever. I also like to do things for people. Which is where the problem comes in. My friends and family know I don't have a lot of money, but don't seem to understand that I know that I don't have a lot of money. So every time I try to do something nice for someone or buy them something it turns into an argument.
"You shouldn't have done that! You can't afford it!" or "Let me pay you back!"
"No, that's okay. My treat."
"But you can't afford that."
"Oh, can't I? Here I thought I was a million-fucking-aire! Silly me!"
Honestly, I know I'm fucking broke. I know it better than anyone, that's kind of the thing about being broke. So I really don't need everyone pointing it out to me every fucking time I do anything. I understand you're trying to help me out, but you're really just making me feel like a bigger loser.
I don't know how I can make this any clearer but when I do have some extra cash, it makes me feel like I have that much more by being able to give things to the people I care about. I get more out of the things that I get for others than I ever get out of the things I get for me. And it just sends me crashing back down when I have it thrown back in may face.
It's a gift. Say thank you and take it for what it is. I don't need your pity and I don't need your damned charity.