Not Ready for Relationship?

So I’m 17 and I’d been talking to this guy for a while and I wasn’t sure what I wanted from it so I ended up messing his around a bit whilst I decided what to do. This totally wasn’t fair on him cos he’s an absolute sweetheart but I was just overwhelmed and slightly scared (it was my first relationship)

Anyway, I ended up getting with him (so now he’s my boyfriend lol) but it’s just never felt quite right to me - he’s really into me and I’m just not feeling it but I don’t want to hurt him, especially since I already sort of hurt him when I was deciding if I wanted to be with him or not.

I think I’m just not ready for a relationship and he’s really keen for one - he’s already told his parents about me and tried to win me cuddly toys from a fair and I just find it’s all coming on a bit thick, it’s putting me off that he’s SO into me and I’m finding it a bit suffocating!

So my question is, how do you tell someone you’re not ready to be in a relationship whilst staying on friendly terms?

It’s gonna be awkwarddddddd

EDIT: might also add I’ve a lot going on in my life, eg, starting Uni next year so thinking about exams, applications, also I do sport to a pretty high level and struggle with body image/mental health so all in all I’m not in a good place to start a relationship really..