<human>: Hello all, I've been looking for some breakup advice but have found it hard to find what I'm looking for. 

I've been dating someone for a few months that has been very open about how much he loves me. He hasn't proposed directly, but he often says how he wants to marry me and have kids with me. However, I have come to find in the last month that I'm not really interested in him anymore and want to break up. But I'm afraid that he'll be very devastated by it. I've been trying to keep some distance from him in the last few weeks, but I can tell that he has no idea that I want to split up. I think that he idealizes me into something that I'm not, and he's said many times that he just won't date anyone after me because he'll never find anyone better. (I've tried to gently encourage him otherwise, and that he could be happy with someone else if things didn't end up working out between us, but he will not listen). 

I know that I want to break up, and I don't want to drag it out. I'm just looking for some advice on how to do it. I know that it won't be easy no matter what way it's done, but I've never broken up with anyone before. Please, if you have any advice I'd love to hear it.

Could you distill the essence of the text into 1-3 sentences?
<bot>: Guy is very in love with me after dating for a few months, I want to break up and want advice on how to do it as nicely as possible.