Welcome!
I've had two kids since taking Imuran for a year, so I think you're good on the fertility part.
I think you should take both since you built up Humira antibodies so quickly. The risk of cancer isn't as much - it sounds scary when you hear things "triple the risk of cancer" but if the risk was only 2%, then tripling is only 6% and isn't as bad (I made those numbers up, but you get the idea).
I'm so sorry about
the yeast infections. I get those frequently and it sucks. What have your doctors tried to get rid of them? I also used to get sinus infections a lot and finally saw an ENT. He did a scan and it showed a deviated septum, so things weren't draining properly. I got it corrected and that helped a lot.