I had 4 induced abortions. no complications, menstrual is normal have had 3 miscarriages after. did i mess up my endometrial lining? & is that fixable

No: It isn't the endometrium that is the source of the repeated miscarriages. It is either a genetic issue or cervical incompetence. The cervix may be opening too soon in the 2nd trimester and may need to have a suture placed(cerclage).Genetic issues can be tested at the time of the miscarriage with the products of conception or later with blood testing (TORCH titer).