I am a second year resident (not in the US). I have been finding radiology a little more painful and stagnant feeling that I had thought it would be. As well, my director just advised me he thinks radiology is not for me... One the most enjoyable aspects has been the simple procedures such as US guided injections, CT epidurals etc. I have done emerg for 2 years already (not on the program - similar to UK here) I was thinking of pain medicine as an alternative. Am I totally insane?
Most doctors are insane anyway, so even if you are insane you are not alone.
No one is in the position to tell you whether you are suitable or not for a specialty. They may think so but it's up to you to decide for yourself.
So don't give up too easily. Stay in the game unless someone actively kicks you out. Don't kick yourself out voluntarily unless you hate the field (not talking about current bosses, but radiology the field itself if you were self employed and can have things your way). The people are just temporary. Once you get your fellowship, you can move as far away from them as possible and be laughing.
You need to do a root cause analysis. Shamelessly and sincerely go ask for the people who are failing you or inviting you to quit, ask them to go over specific areas of weaknesses and invite them to help you come up with a game plan to improve. You will also need to have some sort of objective measurements eg. fortnightly brief assessments to show you are improving gradually.
There should also be some sort of support network for trainees in trouble. Some sort of liaison network. Also ask for help from your peers and people just one year above you. Again just let them know you are desperate and are on the verge of quitting, would really need advices, constructive criticisms etc. from them. In addition try to find a couple of nicer consultants and also get regular feedbacks from them.
Hey good luck! A big part of medicine is perseverance.
(But then again if you love pain medicine, then go for it. We all have our attributes and suitable path. We need more good Pain doctors. The waiting list for patients at the moment is just ridiculously long).