in fear of loosing hope

I was 19, It all started when I found out I was pregnant, March 2011they found a skin tag on my neck stage 4 Malignant Melanoma, I had surgery when I was three months pregnant and then at eight months pregnant they told me to have an early delivery for another surgery, this time they removed six lymph nodes from the same area, Melanoma Lymphoma. Thinking I'm done and sure to live a long healthy life with my son and his father. When my not so little boy grew to be eight months, June 2012, tumors were found in my brain, it was removed with surgery. Being in the hospital so long I lost my home, my aunt took my son until I became better.....  Now my family that was created has been seperated. November of the same year another left temporal lobe was found, now two. Surgery and gamma knife. My aunt still had my son from me and my boyfriend worked for room and board. Now April 9, 2013 they again removed a tumor, but now  the right frontal lobe and two other tumors one left temporal lobe, the other right temporal lobe. I have been on and off Zelboraf, 4 in the morning and 4 at night. If your math I'd bad this is about 2.5 - 3 years of cancer. My aunt still has my son, I'm 21 years old. How much longer do I have?