15 week baby? Ready for solids?

Ab

My baby is 15 weeks and turns 4 months next week around Thanksgiving. She has been breastfeed since day one. For the past month she has woken up at night almost every hour to nurse! I tried soothing her other ways prior to nursing but she just wants more milk! One night she even woke up every 45 minutes. I’m exhausted. Recently we started her on some rice in her milk prior to bed but that maybe helps her sleep 2-3 hours at first then back up every hour. She sleeps for the night around 11 and wakes up at 8/9. She has her 4 month check up coming up but we are transitioning to Tricare so we don’t have a pediatrician to call about this. Everyone says my baby looks little for her age and I’m starting to feel inadequate ☹️☹️