How to breakup nicely

I (25f) wants to break up with my boyfriend(26m) we only been dating a few months. I feel really bad because I was the one who reached out to him and wanted to date. He's a really nice guy honestly but after the first month and half I suddenly got like the ick or something. He hasn't like done anything wrong I'm just checked out I think getting to know him he wasn't what I thought at all. Suddenly everything he says just became super annoying to me he way more of the lovey dovey type and is just a lot for me personally.

He mentions very often how bad his ex have hurt him and all this emotional stuff. He's super emotional which makes this harder I like him as a friend just not romantically. He constantly tells me he loves me even when I don't say it back always tells me he doesn't want to lose me. He puts blame on himself for not being good enough which I think he's a good man just not my type of man. He does cross boundaries sometimes and makes some comments that are just disrespectful Plus I feel I'm always repeating myself to him. The only other thing is he is super cocky loves to dish out insults but takes everything personal even when it's not towards him.

I'm just trying to figure out the nicest way to break up with him with minimum damage. Also we are going to be working together which is another reason I don't want a bad breakup.