I feel like he is using me, and I don't get anything in return.

I've been friends with this guy for about a year and idk if I should keep it going or end it. he's 3 years older than me so when we first met I was 15 and he was 18 now I'm 16 and he's 19, he has a game he's working on and I've helped him with some scripting/coding for the game since he'd asked if I could help him out and it sorta became a thing... he would ask me for help or ask for favors such as "can you give me feedback on this?" or "can you draw something for me?" I've prob spent over 40+ hours drawing for him and 2-4 days scripting/coding. He'd also ask me to remind him of things or give him motivation. despite all I did I never got anything in return. And recently he had been accused of something which wasn't true at all... I tried to comfort him, I was there for him and all that, but he never does these things to me... if I'm dry he'll leave and end the call. I do more for him than he does for me and yes I have talked to him about all this, but he doesn't change. pls help...