Hi @MistyBlue. Welcome!
It's nice to have you on board.
Gee, that's quite a tough "catch 22" you're in. On the one hand, your head is telling you that talking to someone could take you on the right path to recovery, but on the other hand, your social anxiety is standing in your way of doing exactly that. It's interesting, too, that when you've taken the difficult step in the past, something was preventing you from fully committing to seeing it through. You sound like you have excellent insight.
Ive been battling depression and anxiety, which have been wrapped up in PTSD (as I've just recently learned). Sometimes I've had good insights that break through the fog, but often I struggle to get perspective to be able to communicate like I'd like to in counselling. Keeping a note pad has been useful for me. I write down observations, like something that's triggered me, something I've identified as an obstacle or barrier, or an "aha" moment. Then I bring it along to counselling and found it really useful because I'm not necessarily feeling clear headed when I'm in there and it gives me a bit of a script to work from.
I wonder whether you've been happy with the people who you've seen about this in the past? It makes such a difference if you have a good rapport with them - that's half the battle. By asking around, I managed to identify a psychiatrist who I thought would tick all the rig boxes for me, but it was several months wait to get in. In the interim, I saw my GP (who is awesome) every week or two for a check in. That made a real difference for me. That fact that it was only 15-30 minutes max made it a little less anxiety provoking for me too. Some GPs are actually trained in CBT so might be able to get you started with that and/or meds as appropriate, till you feel you're ready for the next step? Just a thought.
Another option, alongside a GP, might be to look into some online therapy or programs, so you can have more of a sense of being in your own driver's seat.
Btw, well done for your decision to join the online community here! I imagine that might have taken a bit of courage under the circumstances. 