Hello and welcome, I'm sad to hear your story, I hope that everything will get eventually good for you, although I doesn't have had as much troubles as you I've suffered as well as chronical depression and I know it's a whole lot of bad time, can't imagine how it is with all your other problems.
About the tattoo, if you really want that tattoo it woudln't matter how old you are, but, since you want a meaningful tattoo I wouldn't recommend to ask recommendations to people, if it is something you came up by yourself it will be a lot better than a sugestion, so take your tiem and don't rush. (I'm not saying that is bad if you ask other people at all.)
Good luck with your tattoo! And I sincerely hope everything gets better soon