Speculation but you maybe you need more rest and/or food after 2 days of 25-30 mile rides. Hitting that 3rd ride in a row seems to be stressing your body.
Losing 43 pounds in 4 months is impressive but you’re in a big deficit so that would impact recovery as well I would think.
Youll find a balance.
I have been doing 15-20 mile rides with intervals incorporated. I do these rides on Tues, Thurs, Sat, and then a less intense ride Sunday. On the off days I do strength training.
Ive been steadily losing weight but did it with a pretty small calorie deficit daily. I imagine a big calorie deficit and fasting combined with burning all those calories could impact your recovery a bit.