Please help!!! confused about my Ureter cancer

I am hoping someone can help me understand. I am 48 yrs old. In Nov i went to a walk in clinic complaining it hurt when i urinated...they called couple days later said there is no infection just a small trace of blood in urine nothing to worry about..A week before Christmas i went by ambulance to hospital they did cat scan said they don't see anything except enlarged kidney must have been a stone follow up with urologist..Dec 28th went for ultra sound they said it showed same as the cat scan..come back for more tests..On Jan 9th i once again was rushed by ambulance...this time they did an emergency surgery to see why I was cramping so bad..they got in the Ureter and found a tumor...2 days later came in told me I had cancer...On Jan 16th I had surgery once again and now they say the cancer is gone but will go back once a month for 6 months for check up...Question is...why did it take so long for anyone to listen or do more tests? From here what do I need to know and watch for?
I am begging please help me understand..I just recently took full custody of my 2 yr old grandson (before the cancer) and I am not ready to quit...Please help with what ever advise anyone can give me!!!!