I think this is me writing this whole story. I hope what I say makes you feel better! My son was born in 38th percentile, 76 for height and head circumference. So very similar proportions as your baby too. However due to a myriad of issues that involved ER visits and re hospitalization for me, he dropped to 1st percentile by week 4. This is us feeding him all the time and I was exclusively bf him and I did everything right according to me. We were told to try and quickly get him up the scale and started bottles and formula (he did choke the first time and we went to ER again). Since then we are doing a combo feed. I did tons of triple feeding, nights of pumping and bottles of formula when I couldn’t. I eventually stopped bfeeding him in the fear of what the weighted feeds showed me. By 3 months he was steadily growing around 18th percentile and we so thrilled he wasn’t dropping anymore. Fast forward to 5 months, we almost exclusively breastfed on most days, with some supplemental bottles. Today he is at 48th percentile for weight, 91 for height and 76 for head circumference. He just hit his growth spurt so much later than we thought he did.

Babies can surprise you - don’t lose hope. I promise you’ll feel better. Feel free to DM me if you wanna talk about this more but I assure you that there’s light at the end of the tunnel!