Brave of you to own up to it here. It's going to be a hard road ahead, because it sounds to me like at this point, lying comes a little too easily; you may find yourself often lying about things without even thinking about it (like the school thing, maybe). I hope at the very least, you can become someone you're prouder to be.
One point that I feel obligated to make as a veteran... A truly "dishonorable discharge" can only be issued if you were convicted of a general court martial. So unless you stood before a jury of your military peers and were convicted of a crime in a military court, you are likely confusing the type of discharge that was given to you. If you did in fact have a dishonorable discharge you would not be able to vote or own property in the United States, you would essentially have the equivalent of a felony conviction. DADT was a travesty and I'm sorry that you had to go through anything related to it, but if you really do want to come clean about your past it might be worth properly stating the conditions of your prior military service. Best of luck and I hope coming clean as you have works out for the best for you.
That took a truck load of guts to post all of that here.
And since none of those three things has ever come in any conversation with me. So you are safe from worrying about any of that in my direction.
Here is my $0.02 worth of advice. Anyone who is going to judge you on who you were, or where you came from, isn't worth your time. I am not particularly proud of where I came from, I did a similar move across the country, in part to escape everyone know where I came from, and being pigeonholed as that person still.
But there comes a point when you have a choice, you can be someone who fits the roles that other people expect you to fit, or you can just be you. It sounds like you are on the second path. And if you need a shoulder to lean on anywhere along the way let me know.