Breastfeeding suddenly not working after 7 months?

I feel so discouraged, I’ve been exclusively breast feeding for 7 months, we introduced some solids around 4.5 months. In the last 2 months my baby has just stopped gaining weight. I don’t notice any supply differences when I pump and she still eats every frequently (about every hour during the day, and every 2 hours at night). I’m trying to see a lactation specialist but my insurance doesn’t cover it so I’m trying to limit the appointments. I’m so confused, has anyone had an experience like this?