How to relactate?

Hi mummies! I gave birth just 2 months ago and suddenly i got my menses back. I was exclusively breastfeeding so was surprised that my menses came back early. Then my milk supply suddenly dropped, like ending soon. Even with breastfeeding supplements (fenugreek) it seems that my supply is not increasing. I also had lactation massage but also did not help. Any advise please? I feel so defeated that i cannot feed my baby well.