I've not reached 3mths pp but way before pregnancy I did see a dermatologist for my hair loss and scalp issues. You can check out Dr. Teo Wan Lin's products, she has them available online for home delivery. I found her shampoo and copper peptide solution useful for regenerating hair. Quite pricey but they helped me grow more hair. https://drtwlderma.com/haircare/
Also, if there's a lot of baby hair coming out, it means they'll grow back and the hair follicles are still working!