I would suggest going to a psychiatrist instead of a psychologist if you can. Psychologists although they make good talk-therapists however, they don't have the further education or ability to prescribe you medicines you need to help alleviate yoru symptoms. I started off on taking anti-depressants from my PCP and that really messed me up for quite some time and I ended up in the ER one day trying to commit suicide.
Since then I went to a psychiatrist and I absolutely love him. he makes me feel normal, tells me there's nothing wrong with me, has really been administering my behavior and making sure he keeps me on the low end of dosage so i don't develop any immunity to a certain med. You have to realize that the brain is the most powerful organ in the human body and it make you feel any which way it wants. YOU have to fight it and have the ability to move on and live for the good things out there. Sometimes the healthcare industry seems all about making money but if you can find that combination of a good doctor who genuinely cares and is interested in getting you back on your own feet, it really helps!
Good luck with your meeting and don't be afraid, there's ~2.3 million Americans currently diagnosed with bipolar disorder so you have plenty of support and friends on this forum.
I agree, you must tell the Psychologist exactly what you're feeling just like you've described in your post. If you're only on anti-depressants and having these feelings it may be a 'mixed episode' you're having...anti-depressants are renowned for causing these states in a person with Bipolar. You really need to see a Psychiatrist for a proper diagnosis. It sounds like you're feeling angry at the world and aggitated, I was exactly the same before being put on a mood stabiliser.
The reason why you've had to wait around to see someone again is probably down to the good old NHS but once you're properly diagnosed and under the correct care of a Psychiatrist you should get the support you need.
Good Luck, and be totally honest about all your thoughts.
I would assume that they would have you see a psychiatrist as well. I am not sure why there is such a long waiting time. Make sure to let them know about any of the thoughts you are having so they would know how to best help you. It makes sense to see a psychologist who is a talk therapist as well as a psychiatrist but they can't prescribe medications as they are do not have a M.D.. Sometimes a person sees a psychologist who consults with a psychiatrist afterwards and they make the decisions about medications. That can be done for insurance reasons and its not neccessary a good thing but that's one possibility. Best to ask them directly.