Tongue tie is a nightmare & totally agree that there is so much pressure to bf but not enough resources/info post birth to help with bf!
Both of mine had a tongue tie..I got DS's snipped on NHS when he was 10 days old but was really struggling with bfing then (was told to express in meantime which obv dwindled supply). With DD I had hers snipped privately at home on day 4 as my milk came in...made such a difference & NHS were 3 wks to even get a referral never mind treated.
A tongue tie is basically where the bit of skin between the tongue & floor of the mouth (the stretchy bit,called frenulum) isn't stretchy or is short & tight. Means baby can't get tongue out past the lips or gums...this in turn means that the tongue isn't long enough to cushion the nipple when breastfeeding, meaning lots of sucking from baby as they struggle to try to get the colostrum/milk & shredded nipples for the mum (mines bled too).
There's a big push/campaign by the nct at the mo about better resources for tongue tie. There's new research out there now too...it can be hereditary but there is some suggestion now that it could possibly be linked to taking folic acid supplements, however the benefits of taking the supplements far outweigh the risks..
I mixed fed both due to it (DS was dehydrated when I got home from 1st night in hospital...he would cry to every hour to be fed but would be asleep within 10 mins as he couldn't get anything/was shattered.. Every mw u asked in the ward that night said its fine, he's raking what he needs...but he passed some blood in his nappy when I was home. Tongue tie was finally picked up next day at discharge). As a result if my experience with DS, I got DD checked straight away for TT & also took in a starter pack of formula to hospital just in case. She had no problem whatsoever in switching between bottle & nipple tho I oh managed to bf til 9 wks with her as I kept feeling guilty about DS when I was feeding her (he always wanted to play etc with me & was always seeing me stuck to the sofa with DD stuck to me for a feed). But if I knew then when I had DS what I know now, I think I would have persevered with BF 1st time around.
That's just my personal experience...& with 3 under 4, I'm probably going to mix feed again, so that DH can help with the feeding too...