Hi, I'd like to help you with your question.
It sounds like you have an anxiety disorder with some possible mild depression. I say mild depression because it is common for depression to accompany anxiety. Sometimes people will feel depressed because they are anxious.
With anxiety, it is very normal to go from one end of the spectrum to the other in your though process. This is the nature of anxiety and causes a person to feel out of control. But you are not. It is a thought process that you can control with the help of therapy and self help at home.
You did not mention a diagnosis. Has anyone done and evaluation on you? If not, you may want to consider seeing a Master's level therapist to help you obtain one. It is important that you know what you are dealing with so you can receive the best treatment possible. Try asking your doctor for a referral. Or you can search on line for a therapist at http://www.itsgoodtotalk.org.uk/therapists/ or http://www.bacp.co.uk/.
If you had a bad reaction to your medication before, it is probably a good idea to not take it again. Some medication causes worsening of symptoms or can even cause new ones to appear. But it is very common for people to need to try several different medications before finding one that works for them. One medication that most people feels helps is Ativan (that is the name of the medication in the U.S.- check with your doctor about the equivalent in the U.K.). Ativan can be taken as you need it or on a prescribed basis.
I also highly recommend you see a therapist. Although medication can help you cope with the symptoms you have, it does not help you work through the problem and solve it. Therapy can help you find the root of the problem and find ways to recover your health through talk therapy and working on the issue at home. Anxiety is a highly curable disorder and therapy is very effective in treating anxiety.
Also you can work on your anxiety though self help. Here are some great books to get you started:
The Anxiety & Phobia Workbook (New Harbinger Self-Help Workbook) by Edmund J. Bourne- An excellent book I highly recommend.
The Cognitive Behavioral Workbook for Anxiety: A Step-by-Step Program by William J. Knaus
From Panic to Power: Proven Techniques to Calm Your Anxieties, Conquer Your Fears, and Put You in Control of Your Life by Lucinda Bassett
The Depression Cure: The 6-Step Program to Beat Depression without Drugs by Stephen S. Ilardi
You can find these on Amazon.com or your local library may have them for you.
I hope this has helped you,