MLM, you don't have to have very severe mania to have some form of bipolar, hypomania is the less manic phase which may still mean you have some form. To be fair though you have so much insight into your moods feelings and behaviours that it may not be diagnosed as such. Whatever it may be though your doing the best thing for you.
It might be beneficial to keep a diary, if you don't already and keep track of feelings and also things like amount of sleep, mood and energy levels. Also speak to people close to you, do they notice any difference in you? It might also be useful to have them go to the initial appointment with you if possible.
Whatever happens though remember we are all here for you and if you need anything from me or I can help in any way please just ask. You have helped me so much in the past x x
Hugs x x