Pls I need a love advice...

Ok so I'm a girl in first year of uni and in september a second year asked me to kiss her and to start something serious after just knowing each other since a few hours, I said no and preferred waiting instead just to see if it could work, I've never been in a relationship bf btw, we became close but it was a bit awkward and in november I confessed to her knowing that she would reject me so that our relationship could become better, I didn't really like her at that time so her rejecting me wasn't a problem and the relationship we had right after was comfortable, we still talked a lot and it was entirely platonic, but now we became really close again, even more than before, and I started opening up to her, I think I am now harboring love feelings towards her but I'm nearly sure it's not the case for her so what should I do ? Confessing while risking to lose our relationship or holding it in (now it isn't painful but I'm afraid of the evolution which may occur :/) and just wait ? She's leaving in june to another country so I don't have much time left to either go out with her or to repair our relationship if I confessed and am being rejected, started a platonic long-distance relationship would then be hard :/ So what do you think I should do ? Thanks in advance!!