Experiencing mom guilt

I had my son 2.5 years ago and was able to breastfeed for 18 month without much issue. I would pump and give him bottles and he gained fine (even though I considered him small he was always under the 25% for everything). He would have enough diapers and was meeting milestones.

Now I’ve had my daughter 7 months ago and we breastfeed as well and she would never take a bottle. The first 3 months was great. She was gaining well, pooping regularly. All of a sudden she wouldn’t nurse as frequently. She would nurse every 90 mins and now went 2-3 hours. I thought it was fine. She would nurse 5-10 mins and my breast would feel empty or softer or I just got used to my supply regulating. In 3 months I pumped 3000 oz. I had a huge oversupply. I still have the milk.

At her 6 month Appt she dropped percentiles and is now in the 7%. I quit pumping after awhile because I wasn’t so engorged anymore. She also would go days without pooping but I was told that was normal for a breastfed baby.

She’s meeting her milestones but she’s 7 months and 13lbs. I have a weight Appt to check on her on Friday to see if she’s gained anything in the last 6 weeks. So I finally got her to take a bottle last night and I’m super happy about it because now she can use the milk I’ve pumped and increase her intake. The doctor did advise me to feed her more solids which we have been working on too but I’ve always been told milk is more important at this age. I’m just so upset with myself because after giving her 2 bottles yesterday I pumped twice and I got 1.5 oz after not feeding her for 2-3 hours. I feel like I should have gotten more than that. I know my pump output my not reflect my real output that she can get but what if it does in this case? I’m thinking maybe I should feed her the milk I pumped for her and then give her formula after it’s done. I’ve tried my best. I know this is long and if you’ve gotten this far thank you. I just feel so bad. But she didn’t take bottles until now. I would have given her formula back at 4 months if I had known I was having supply issues.