How difficult would it be to have my tubes tied?

It's harder than you think. There's a lot of resistance to sterilizing younger people. I had a vasectomy when I was in my 30s because I was done having children and my wife and I didn't want to have to keep using condoms or worrying about it, and I still had to deal with a doctor asking me if I was "sure." Yeah, I'm sure, or I wouldn't be here. That's like a grocery store clerk asking if I really want that head of lettuce in my shopping cart. Not only that, the copay was ten times what it was for any other procedure, including the [i]entire cost[/i] when my kid was born.