I'm always feeling sick now and tired, lately my joints been hurting and ive lost over 100lbs in two years. Cancer Symptoms maybe leukemia?

Weakness weight los. Your symptoms can be because of multiple problems, you should get your basic blood test including CBC kidney function test urine analysis PSA levels, may need endoscopy and colonoscopy. May need CAT scan as well. First of all you should see your primary doctor. .