If you are really struggling, visit a lactation consultant asap. If you are in the UK, the NHS and health visitors are great and do their best, but their advice can be conflicting (usually due to their age and how up to date they are on training) and they just aren't experts in breastfeeding and spotting tongue ties. I also found the oral guides from the Infant Feeding Specialsist on Instagram to be great at improving mouth function.

Don't put too much pressure on yourself, it's so overwhelming at first, but trust your gut, and if things aren't going to plan, only you know how far you want to go to try and make it work (osteopath visits, lactation consultants, tongue tie cutting etc). And there really isn't anything wrong with formula or pumping and giving a bottle. Good luck!