Thinking of breaking up with my (M18) casual partner (M36) because of age gap, would we be able to be friends as exs?

So in the first place, I met this guy who was 36 on a hookup site. I wouldn't date somebody with that big of an age gap, but I thought that hey because this is just a hookup, I didn't really mind the age gap. We met up, and we really really liked each other. We bonded so quickly.

We've been together since mid December last year, and are still together now. We aren't an official couple, I specifically said that when we were starting to catch feelings for each other that this is a purely casual relationship, because we can't date with such an age gap. He agreed with me, and we even said that we are allowed to date other people and have sex with others etc etc. But neither me or him have this entire 6 months. We have done loads of fun things like going to nearby cities, going to the seaside, binge watching my favourite TV shows, etc. It's been amazing honestly. Besides that, physically he is totally my type and I am totally his type.

Now, I'll be going to uni soon, and I just recently said to him last week that when I go to uni, I will most likely not meetup with him until 6 months have passed, so that my heart can move on, and then we will continue our relationship but as friends, without romantic or sexual involvement. We would still text during these 6 months. He seemed upset about it as was I, but we both accepted that this is what we should do. I am the type of person where I can only romantically love one person at a time, and I worry that I won't be able to move on from him if we do meet up again after those 6 months. And even the texting, would I be able to let go of my feelings if I'm still in contact with him? This is my first ever relationship, and I feel ashamed that I'm even in this silly position in the first place.

The most ideal situation would be that we text for 6 months, meetup every now and then as friends, with all my romantic feelings gone so that i can date someone my own age. But I don't know if that's how it works, or if I just need to cut him off completely. But I really really don't want to do that, because I really like him, and he's been there for me when I really needed the emotional support.

But then again, even if he was closer in age to me, I don't think we would make a good couple. He's very anxious and we offset each other a lot. We have quite dramatic arguments then really passionate love after to make up for it, but I don't think that's right either. He can play the silent treatment a lot which rubs me up the wrong way.

So, does anybody have any advice?

TLDR; I have been in an unofficial relationship with an older guy, and we have agreed that we are going to try and be friends instead when I go to uni. However, I am afraid that I might still have feelings if we do that