lookout Can you possibly find your way to your local sling meet? www.slingmeet.co.uk
The problem with slings is that they?re very personal. For instance, I?m a very experienced sling user and I own pretty much all types yet I was unable to feed in a Moby. Loads of people can though! I found a pouch to be perfect for feeding a small baby in - yet getting one to fit is a minefield. Really it's best to try a few different ones together with people who know what they're doing with them. Baby Bjorn slings are never one I recommend. They're not comfortable for mums or babies, and they're ergonomically poor (please don't ever wear your baby facing out in one - or in any sling).
For a high needs tongue tied baby they are usually very settled in a good sling. My personal experience with my TT DS2 was that he lived in his sling because he needed to be close to me, have free breast access and it allowed me to care for DS1 (and do the washing!!). I found that nursing tops which have a lift up flap just below the breast was perfect for using within a sling.
You might consider looking at cranial osteopathy. TT babies usually have compression which can be really helped by CO - both to release the tension which helps them to settle better, and to help them to feed more easily.
Your key to success is as deep a latch as possible. The exaggerated latch you've been shown is great (maybe go back for another session?) and rugby hold can help, too.
You're very much not alone. We're BFing at 16 months so it's all possible.
Oh, and beds don't need changing. Honestly, nothing bad is going to happen 
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