The situation sucks, but you live through it. Please trust that things will get better. Time will put a distance between you and this wound. For the meantime, assess your situation. If you can't feel good about what you are doing, it isn't worth much doing it, at least in affairs of the heart.
Life is short.
Don't drag out your mourning if you don't need to. Or, if you think it will help, pursue the relationship until it is clearer how things will turn out. You'll learn from your actions, either way. Best of luck in this difficult time. My boyfriend and I have been together for two years now, and he recently started working as a hospital doctor.