Pregnant 7 months PP and Losing my Supply


I found out I am pregnant earlier this week, since then I had my HCG bloodwork done 48 hours apart. My HCG triple in the 48 hours and I've noticed a massive drop in my supply. My son didn't have a wet diaper overnight usual and didn't have quite as many as normal yesterday, not a huge a difference but noticeable. I used to have a massive let down that I felt and now it rarely comes. I think I might have to start supplimenting formula. I'm so disappointed in myself and am regreting this pregnancy. I love nursing my son, he loves nursing, I'm not ready to stop but because the drop is due to hormones I dont know what I can do to get it back. Anyone else go through this and were able to reverse it? What are the best organic formulas for breastfed babies and how is it best to make the transition if I cant get my supply back?