Breastfeeding Question

So I decided to start slowly weaning last Thursday and I took one feeding away (middle of the day lunch feeding) and now that I’m approaching the 1 week mark I feel like my supply may have totally tanked with it. My LO has been good with night feeding lately and she gets up once but I feel like she’s trying for awhile before she gets anything...that and my boobs never get “full” like they did just a few weeks ago if I didn’t empty them by 5-6 hours. How do I know when my supply is dwindling? I just don’t want to short change my baby. I gave her her morning feed today and then a bottle she didn’t drink much of but she also isn’t 100% sold on the formula so I didn’t want to take away another feeding until she started to take it better...ugh.