Hello!
I was on cellcept too and now they changed it to smth milder. I haven't really had an infection despite being on it for 2 years. I can see why you want that tattoo so badly. I have a design I really want too, and I guess the idea is kinda similar to yours, something to mark this huge turmoil in my life that swept me from my feet at about 19 too. But I guess, it'd be a good idea to put it off till your condition stabilises? And make sure you don't get that easily infected? Perhaps look for alternatives of a smaller scale?

That's just my 2cents worth, really hope you consider it carefully because it could be a matter of life and death.