I almost feel like I dont know how to answer this.
For me, there is no doubt that its Not Selfish, I would go in a heart beat.
But I dont really know your situation, My DB wouldnt think twice about me doing something like that and would probably pay for me to go. We encourage things like that in each other's lives.
To me, it's your husband that is selfish if he doesnt want you to go, and he's reflecting his feelings of selfishness on you, (Thats IMO, again, I dont know your situation).
But there are some couples who cant do anything with out each other, My mom is an example of that, she will not even visit me unless her husband has his own plans, then she'll schedule her freedom. I dont agree to it, but it works for her. So I'm happy for her.
I'm sorry your going through so much right now, reading other posts, I got a little insight to your situation and I think you need to take care of you, do whats best for you so you can be the best YOU you can be.
Maybe you and your husband can agree to disagree, if he's open to that, maybe he wont like you going, but maybe he can be supportave anyway, I dunno, sometimes men will say the woman is selfish because they dont believe they can handle life with out you gone, but thats not a reason to hold you back, He's strong, he can do it. People do it all the time.
Good luck and ~Big Hug~ to you.