Health issue unable to complete the notice period

I'm having health issue like severe back pain, because I got aborted in the office due to work pressure of my company,at that time they didn't treat me properly,even I'm a pregnant even though they forced me to work, after I had take 45 days leave and again I'm returned to my work,I had finished my bond period but I'm not able to work further I'm getting continuous back pain,I had submitted all my health documents to the company,and I had resigned,but now they are forcing me to serve notice period,even they are not thinking about my health, my doctor districtly adviced me to take take complete bed rest,so what I have to do now ,they are not ready give proper relieving.I informed them I will pay those 2 months salary also,even they are not giving me proper reliving and saying that they will move to abscond. Please guide me what I have to now?