Possible lip tie causing issues?? Sorry kinda long

My little guy is 4 weeks old tomorrow. He was breastfed for 2 weeks but we had too much difficulty with latching. He would also want to sit for an hour or more at a time to feed which was just not doable with having a 2yo. We switched to bottles 2 weeks ago and he still sometimes has a very hard time latching to the bottle. After finally looking in his mouth he appears to have a pretty tight lip tie. Im not 100% certain as I am no doctor. We go to the doctor Wednesday and I will be inquiring. He also takes in crazy amounts of air to the point that you can hear it and feel it move through his body. This then results in awful gas. He seems so uncomfortable while eating I feel so bad. He acts hungry literally 24/7 because sometimes he can only eat an ounce or so at a time (assuming it depends on how much air he has built up, he pulls off the nipple screaming). Our doc says based on his birth size he should be eating 4oz a feeding by now, so it bothers me he may be underfed. I try to burp him constantly and he rarely burps. Not sure why. Gas drops do not seem to be affective. So after researching a lip tie and all the signs he literally has like all of them except reflux.

I am wondering if anyone else has experienced this and what you've been able to do to help?? I thought about switching to a different formula for gas? But don't know if it would help? I can't stand to see him so squirmy while trying to eat, etc. He doesn't appear to have any digestive issues that I can tell. Our daughter was a severe reflux baby with a milk protein allergy and he doesn't have anything like she did. Any advice would be appreciated. I'm hoping our Dr will be able to help too.