Help please medical emergency

I have been dealing with heart issues  colitis bulging back disc . I am 66 yr old. only get 668.00 month social security. have job but miss so much work and no sick leave. as a cashier low pay when do.  gotten point where cant see stomach dr cause have 160.00 past due but also cant pay tax on house.  cant pay bills, haven't been able to get public assistance. have to chose med or food at times. don't want to beg, and would never take more than need. cant work much longer cause of all health issues. have no family except who is unemployed at this time.  don't know where else to turn.