Disclaimer: This is my first time posting on Reddit. Also I am French, English isn't my first language. Finally my emotions are all over the place, so thanks in advance for bearing with me.

TLDR: I'm in love with a guy, but I'm leaving the continent in a few weeks, and there's no chance he'll come with me as he has his own life projects. what should I do in the meantime?

I (29M) met a guy (30M) about 2 years ago now. When we met we had both just got out of long term relationships, weren't ready to dive into something serious. In fact the reason we met was just for hooking up.
Turns out, we really clicked, and started meeting on a regular basis (maybe once every 2 weeks or so at that time), for hooking up, but also because we got along quite well.
From the very beginning we made it clear that no matter how well it went between us, we wouldn't ever make it serious. The reason for that is that we both had very distinct projects for our future. He wanted to buy a house in the area (which he since did and I'm very proud of him) and I planned to move abroad (Moving from France to Canada in two months). That was always clear. He is very attached to our birth region, all of his friends and family members live in close distance. And I cannot compromise on travelling, as I have repressed that in my previous relationship.
So we went along with this, for a long while, and eventually we did everything as a couple, while still regularly communicating about how our respective projects were progressing, and expressing that even if we wanted to, we could not start a serious relationship, as it would mean one of us should abandon personal projects. Not a really healthy start for a relationship.

Around the end of last spring, we had a serious conversation. He had just purchased said house, and I had just been approved for my working holiday visa in Canada. we decided it was best to stop acting like a couple, and to keep things platonic. It was a bit hard at first, cause we obviously both developed feelings overtime. But we managed to overcome this, and to be good friends (or so we thought). We spent a lot of good times together (I've become close with his friends, and he's become close with mine) and truly we considered ourselves best friends at that point.

Flash forward to July. We had a party at his house, and we drunk flirted. I didn't think much of it at first. But he started confessing how sad it was that I was leaving, that I couldn't stay and be his boyfriend. We kissed, hugged, slept together (no sex) hugging. It felt really great, and I seriously questioned my projects at that point. Two days later he had a date with a guy, and only a few days after he announced me shyly that he was in a relationship with that guy. I was devastated by the news, as it was really unexpected.
A few weeks later, he dumped that guy. When I asked why, he told me that he was great, but he wasn't me, saying that he wasn't able to envision himself in a relationship right now if it wasn't with me. All of this got me seriously confused emotionally, and I didn't know what to do.
Flash forward to last week. He told me he had sex with another guy. We sat and I told him it felt weird hearing that, that of course we weren't together and I had no right to tell him otherwise but that it still hurt a little. He said he understood, but that it was important that we should eventually be able to talk about these things.

So here comes my question (thank you if you've had the patience to read all of this):
Since we've decided to keep things platonic, I've convinced myself it was better this way, to make sure that we kept a great relationship, without having both our hearts broken the day I leave for Canada.
The funny thing is, all of his friends are trying to convince us to "enjoy the time we have left to the fullest" (meaning acting as a couple, having sex, etc.) And I'm realizing that's what I want as well, even though we always tell them that "no we don't need that to enjoy time together". Truth is, the only thought of imagining him with this other guy low-key gives me panic attacks.
I know I'm leaving soon, and there's nothing that'll change my mind on it. But in the meantime, I'm still here. And I think either way, our hearts are going to be broken when I do leave, so why not living to the fullest the last weeks we have together? All I want is to kiss him.

Should I tell him what's on my heart?
Sometimes I have the impression that he feels the same, and that confessing will have him admit this as well, and evacuate all this frustration we have. But in the meantime I am also terrified that I'm the only one thinking all this, and that if I confess not only will he reject me (which I think is there part I could handle) but that it will ruin our relationship and that I'll lose my best friend.

Thank you for bearing with me, it means a lot and I hope this post will get approved with this length.
What should I do??