Advice/encouragement needed!

I’m 9 weeks pregnant and still breastfeeding by 8.5month old. All of a sudden this week it seems my supply has dropped significantly. I’m needing to supplement from my freezer stash. Trying to nurse as often as we can and pump as well to build more of a stash. I don’t know if I’m doing this right. So sad if we need to stop breastfeeding before 1 year. Has anyone been able to breastfeed while pregnant? Anyone had a dip in supply but it came back? I hear there isn’t much you can do about the effects of pregnancy hormones on supply, but I’m staying hydrated and trying oatmeal and lactation cookies anyway. Any advice or insight would be soooo appreciated! Thanks!