Firstly hun, huge hugs. Secondly, yes babies with reflux can and do projectile vomit, i had this with my first baby, he was breastfed and winded very well, but he would still projectile vomit. My HV said was reflux, my GP told me that babies do posset, and to stop worrying as he was gainig weight. In the end, he outgrew it when he started being upright a lot more, but we saw a significant improvement when we started weaning. When he was 4 months old he went onto formula as i could not keep up with demand milk wise and the projectile continues, so HV told me to put him onto hungry baby as was a thicker milk so may be slightly heavier and may stay down better, we saw a small improvement, but not massive. When we had 9 month check up HV and GP were there (Different GP) and HV asked about the projectile and a i said was gone, but had been a worry, and GP said, ''well babies with reflux do prjectile vomit, nothing to worry about mum''. I explained about our GP and the posseting and the new GP was furious, he said that as my baby was slightly early at 38+2 and had been breech and wedged since 26 weeks until birth he was much more likely to have reflux and was a classic case, and should have been medicated when first seen. The main thing is he outgrew it, my second baby was vomiting when in nicu and being given formula until my milk came in and they were like ''Breech baby, must be reflux'' so when we got home, his weight gain was poor and mw slagged off my milk and said if i didn't put him onto formula (The same as in nicu) to aid his gain she'd have him re-admitted, so i gave in and gave him formula and the vomiting started again, so this time we had gaviscon prescribed, but it didn't help, so i went against mw and changed his milk to a brand i liked and trusted, and he was fine, weight gain went well, and he stopped vomiting, maybe worth mentioning, he never projectile vomited. It's weird, but my lo with reflux couldn't get diagnosed for love nor money and my lo without was mis-diagnosed with reflux, to be on safe side.
As for over feeding, no you are not! When my second lo was 4 months old, he was on 9oz 6 times a day, and would vomit after the last one, after 3 days of this called hV and she agreed we could not go like this, and said for god sake wean him, he needs it, just do it. You will always get someone who says you're over feeding or under feeding, or breast is best and anything else is evil, or formula is best and breastfeeding is wrong, and it goes on and on, but whilst they are entitle to their opinions, it does not mean they are right. It's what is right for you and your lo that matters, i hope you manage to get his meds changed, my friends lo, had extremely bad reflux and he wouldn't even take enough feed to get the full dose of gaviscon, so she was given something she has to measure and syringe into his mouth, possibly ranitidine but not 100% sure, and he was better on that, she has to give more some days than others, but he is fine, but the screams and vomits nearly drove her mad, it started to make her ill too with worry and seeing him in so much pain, but like i said now he is fine and healthy, he's not the biggest baby in the world, that would be my lo, lol.
Really hope this all gets worked out for you both hun x