sounds like you're doing a fab and very caring job
re; the windiness. agree with the Dr Brown's bottles and winding through feeds. both mine have been bf with bottles of ebm here and there. they both needed winding after boob or bottle just more so after bottle (ie better with breast but still an issue). i think its a common myth about bf babies not needing winding - all the ones i know (quite a few!) have needed winding most of the time. as mentioned by a pp, a fast letdown may make thhings worse.
at 7 weeks, baby may have colic - has you or mum tried colic drops? there are lots of options out there (infacol, dentinox colic drops, gripe water, colief) ans different babies respond differently to each. infacol was rubbish for my boys, despite friends swearing by it, whereas dentinox was amazing stuff!!
uf baby is happier upright after feeds, it might be worth considering reflux. the valve between stomach and oesophagus may not be completely developed, which isn't uncommon and usually resolves itself with time. keeping upright as poss for at least half hour after feeds may help. worth seeing a dr if its making baby really uncomfortable/excess vomiting/not gaining wt. my ds1 had awful gripingpains and used to cry just to pass a teeny bit of wind which turned out to be a dairy allergy easily diagnosed after his first bottle of formula (around 5-6,onths). intolerances can be a but more tricky but worth bearing in mind.
just some thoughts for you to consider. sounds like baby has been much happier after ebm though - long may it continue!