Firstly, I'd just kindly reinforce that the guys on here who give out way more advice than me are very knowledgeable, and they're not just saying things to annoy you. It's definitely worth baring in mind that you never know who you're talking to on here....the RAF is a small community. But I do get it, the application and selection process can be frustrating. Mine was. It took well over a year from me sitting a p2 pres to signing on the dotted line.
It can take a long time. The speed you go through depends on you, the speed of your afco, and the speed of whatever part of the process your at. For example, if Capita medical services are busy, then they're busy and you may have to wait. As mentioned, no one on here can offer medical advice as we aren't qualified, and I do totally get your frustrations, but that's just the way it is.
I'm not saying you have to have had a dream of joining the forces forever, but it shouldn't be decided on a whim. I'm not saying that's the case for you, but it's a very big commitment, so you have to be sure.
All the best and hopefully this has helped a little bit