I was in a similar situation once. I'd been in a relationship with my boyfriend for almost a year when we discussed the fact that he was going to university. I didn't know what to do either, whether to end it then or wait until he left.

I chose the latter option, we said goodbye on the day he left and I never saw him again. It was very painful and I found it difficult to "get over" someone when there wasn't a reason to be angry with them.

I wish I'd ended it sooner if I'm honest, it would have hurt either way but by letting it continue up until the point of them leaving left me feeling like a time filler, even though the love we had was genuine. During the last 2-3 months I was extremely aware of the expiry date. When we went for dinner all I could think about was that it might be the last time we would eat at that restaurant etc. It was hard and I felt like it was just dragging out the pain.

I just wanted to share my experience in case it helps you.