Thanks for the inputs..
I shall answer your queries one by one.
-- You should take the afternoon dose of clonazepam at 1-2 pm. But if the need arises at times of abrupt onset of anxiety / panic attack then you can taken 1 tablet of clonazepam in the morning too but it is unlikely to develop due to your night time intake of clonazepam and usually clonazepam is given in twice a day dosing, not thrice a day the way your doctor has been giving you.
-- I do not think you will have any withdrawal side effects if you discontinue morning clonazepam reason being you will still have enough. probably the right amount of clonazepam in your system to work for your symptoms without any withdrawal symptoms to develop.
-- No, quetiapine should not be taken throughout the daytime at any point and only night time dosing should be continued , you see quetiapine has a 24 hr long half life which is enough to allow it to have an effect whole day long in a single daily dose, so a night time dose shall be sufficient , yes the dose at night time may be increased by 25 mg every 1 week to as high as 300 mg/day if the need arises but I feel as of now you should stick to your current dose.
--- Yes I concur to your mentioned format of clonazepam intake, kindly continue it and at times when you are feeling anxiety despite taking the regular dose then you may take 1 more clonazepam tablet over it.
-- Yes you shall continue taking B12, it is a good supplement to help your cause plus it has no side effects. You shall continue taking it for at least 1 month.
-- As far as why marijuana use made you feel better is concerned, the reason lies in the fact that marijuana has a tendency to mask one's subjective emotional tone aka feelings and provide a sense of tranquility and peace within and therefore people tend to stay on it quite unaware of the fact that it has a lot of abuse potential and it causes life threatening addiction / dependence , so it is only better to keep yourself off it.
-- Well for me irrespective of your vulnerability to bipolar disorder, I shall have tried you on a formidable anti depressant drug such as Lexapro at dose of 10-20 mg / day or Zoloft at dose of 50-150 mg / day, the reason being OCD is best managed when a combination of an anti depressant , an anti anxiety drug like clonazepam and an anti psychotic drug like quetiapine are used together , in your case unfortunately owing to your morbid fear of developing bipolar disorder you are only using 2 of the desired drugs which is an incomplete regime and I must mention here that despite using an anti depressant in your case you are more likely to escape bipolar disorder development for the simple reason that you are also placed on quetiapine which is known to prevent manic / hypomanic episodes.
I hope this helps.
Wish you all the best.