Well, a short list:
1) Societal scorn
2) No safe holding hands in public
3) No legal recognition of your relationships
4) Possibility of parents throwing you out of the house when they find out
5) Friends hating/ignoring you
There are many more, but I prefer not to focus on how much life can suck for us, and rather look at the positives. How much do your parents/friends really love you if they disown you or throw you out of the house?
How good would my life have been if I was never pushed to make myself a better person? Most of the people I went to high school with never went to college and had kids far earlier than they were ready. I have a college degree, a fantastic job with Yahoo!, and a wonderful relationship with my partner. I have all of these things because I was pushed in my youth to be better than my peers. It is precisely because of the disadvantages that we start out with, that allow us to excel. Many persecuted minorities, Jews, Asians, gays, end up being very prosperous and powerful in the societies they live in precisely because they are challenged to be better than the majority. It is this challenge that some would say is our greatest disadvantage, but I like to think of it as our greatest strength.