Mouth cancer

Firstly I had breast cancer (stage 1 & grade 1) 

Then this year I had issues with tamoxifen and thankful that after a hysteroscopy all was given all clear...

now I have a ulcer on my tongue that is being checked as it's been there more than 3 weeks. My tongue looks poorly and I am so very anxious...

I don't know where to turn 

so depressed