frustration with ttc

Ever since my miscarriage in April it's been pretty difficult to conceive again. It breaks my to know that the first time trying was really easy but now become my biggest frustration. I suffer from 2 illnesses; Lupus and MS, the Lupus caused my miscarriage 😔. I've tried taking my prenatal vitamins to help me conceive, even taken geritol ... both didn't work... 
Do you all have any suggestions or recommendations? I feel worthless and and I know my husband wants a baby really bad.