I have been natural for 1 & 1/2 years, but i have severe heat and color damage. should i big chop?
If you want your hair to be completely healthy again, yes
If you feel like you can cope with shorter hair yes definitely. If you feel you can't but can manage to deal with the damage then you can trim it every 6 weeks or so so your hair maintains the same length. I suggest you ask your question on CurlTalk to get other suggests that will help you.
Hard to say as the choice is based so heavily on personal preferences. When I had badly damaged hair from some bad colouring jobs and chemical straightening I did a big chop because for me, I couldn't handle having the damaged hair on my head anymore and just wanted to start over. But some women would feel more uncomfortable having short hair than they would with having longer hair that happens to be damaged. Do what makes YOU feel better!