Fertility treatment has begun

Well, finally completed all of my testing. Found out that I have not been ovulating, and that my entire left side is useless when it comes to ovaries and Fallopian tubes.. I start taking Letrozole next month after I start my cycle and get a second ultrasounds to check on my ovarian cysts .. I’m relieved to know what the problem is, but somehow I still feel hopeless and like having a second child is never going to happen for me .. all of the testing is causing a lot of stress and putting a dent on us financially .. I want to grow our family so bad, my son really wants a younger sibling .. and I have always wanted 2-3 kids .. but I can’t help but be afraid that the journey to making my dreams happen, will also destroy me financially and cause even more problems down the road ..