breakup help??

So I need to break up with my boyfriend because I feel like we’re not compatible. ( context, i’m 21, he’s 24). I really do care for him as a person and friend; however, romantically I feel like the spark isn’t there for me like it should be. I am so thankful for all that he does bc I really am spoiled and taken care of by him. The only reason why we’re having issues is from past people giving me trust issues with him and him feeling like he isn’t important to me after i had to take a step back and process everything. I feel rather overwhelmed by the relationship, especially bc we’ve only been dating for 17 days and we’ve had so many issues in these 3ish weeks. He’s already REALLY in love with me as he tells me but I feel bad bc i don’t feel the same. He’s always buying my gifts, sending me random money for things, and always taking me out, already trying to talk about our wedding, proposal, kids…etc. (which is also scaring me bc i’m still really young and we JUST met basically) and i can’t help but feel like a shitty person for still not loving him when he does so much for me. I’m also hesitant to break it off bc I feel bad for all the time/money he’s wasted on me, just for me to not feel the same anymore. How can I go about this breakup or just general advice about relationships when you’re younger/still figuring yourself and stuff out.