The LC can talk you through what you've done so far and where you're at. She may also be able to give you further referrals for releasing TT, if you want that. As for apt times, it really varies. Don't understate the pain you're in when you talk to her Don't suggest it's getting better. Just tell her how it is for you when you feed; hopefully she'll be able to see you soon.
You could try shields - this is another thing LCs can work with you on. It's important if you're using them to a) still be looking at underlying issues b) make sure you get the right size and use them correctly (or can cause more issues) c) make a plan for stopping them (and obviously, this would hopefully dovetail with fixing the actual problem). At this point it may well be worth a try! Pharmacies often stock several brands - it might be worth getting a few to see which suits you best. It's hard to know about sizes, which is where the LC can come in, as well as trouble shooting their use and help with weaning off them.
I'm a big believer in making appointments just in case and then cancelling them if you no longer need them, so that's an option with the osteo (and anyone else you reckon might be able to help).
Sometimes mums can muddle through and things just get better, but it really just shouldn't be like this, you know? If your baby is latching themselves and still not getting it, then there's something else that needs addressing. Babies are born to breastfeed, it's what they want and need, and when they can't, there's a reason why. Good luck with your calls tomorrow.