Bowel and rectal issue. Is it cancer?

I have been experiencing left side abdominal pain for quite long, over 2 years.I feel bloated, pass a lot of gas, knotted feeling in left abdomen which gets eased when I defecate, sometimes acidity too. Also I have had a pimple kind thing on perianal area on left butt for over a year, whose size keeps on changing(sometimes almost vanishes and sometimes gets bigger).Now I have a lump kinda thing on left anus border for over a week now. Pics attached. I poop 1 time a day mostly and max 2 times a day rarely. Check my poop occasionally. It seems normal in thickness in the morning but when I have to otherwise poop in the evening , thickness is somewhat less. Sometimes burning on anus after I poop, and tailbone pain too. I used to spend 20-25 mins on the pot, which I have now reduced to 10 mins max. My CBC indicates low platlet level(110) , low MCV(78) for 4-5 years. HPLC, Reticulocyte, LDH, Iron studies- normal (as guided by haematologist). Is it cancer? Very worried! Guide please.