Help? Ucas extra? Clearing?

Hey!
I have 2 university decisions left, but honestly have no faith in getting in. The course is too competitive and I am a mature student. I've reached out to both and they've said decisions will come late march. I'm going to send an email asking if there is anyway to expedite the process, which is just a hail mary I don't expect special treatment.
2 of the other courses that was much less competive and I planned to use if I wanted to use ucas extra have closed. That's really bummed me out, and honestly I think if I don't get a decision soon I will have to move on. The courses left aren't that great, but I would rather have an offer and be at ease and still have the option of clearing than continue to wait basically. I don't want to get into stats and stuff, just want general advice on if course availability increases during ucas extra. And if clearing during June even has many course reopenings, or if its basically a free for all during a level results day.

Last year, the second course i want to apply for did have at least 10 in clearing but I do have anxiety. So I don't think i can wait if you understand what I mean, should I just be proactive now as I'm even losing intrest in the original course I applied for. I've called a few universities, and they've said they can't assure me that their courses will even still be open during March so I really would be shooting myself in the foot if I choose to wait. Whereas, if I i reject and withdraw everything now and go into ucas extra I am more likely to be in a secure spot i think.