Any other advice for constantly checking/questioning yourself is welcomed!
You have to learn to forget about yourself, stop being concerned about yourself and put your attention "out there" on life instead. This is the essence of CBT you have to recognise your behaviour and change it for the better and if you can recognise that you are always internalising IE: always checking and questioning then you can also recognise that if you could change that behaviour somehow then you would be free-er and be able to find a little more peace, etc.
Well that can be achieved. It isn't easy and won't happen in a week, but it can be achieved and to achieve it you have to work on it. It's a skill that can be learned and just like learning any other skill it takes time and practise to get better at it. Practise is the answer, practise, practise, practise - just like me learning to play the guitar if I don't practise then I won't get any better and so how much you practise is up to you - but if you practise regularly then I guarantee you'll get better.
So jump in and practise - learn how to forget about yourself and put your attention on other things instead.
Look at a bird in the sky for example, just look and really see it without any mental commentary and see how you become enthralled by it. If not a bird, then a pet, if not a pet then a baby, if not a baby then a film, if not a film then a book, etc., etc, etc. just put yourself back "out there" into life and forget about your troubles - that's the way and then if you really need time to check in and discuss your troubles with yourself then just allow yourself 30 mins a day to do so. Set a time whereby you agree with your mind that its OK to check and question, but make sure you have the resolve to only do so for 30 mins a day - because any more than that is just ruminating right!!??.
That's what I did with my mind I told it I would sit down for 30 mins every night and check-in, etc. So then when it tried to check or question itself at any other time of the day I would say to it "Ah-ha, not now - this can be discussed later at 8pm as agreed" and do you know what it agreed, it complied, it was happy to leave me alone until 8pm (or whatever time it was that suited me, the time isn't important - it's the agreement with your mind that is important) and as long as it knew it was going to get my attention at some point it seemed to be quite happy to "shut-up" again (after it was instructed it to of course).
So I would sit down for 30mins and the mind would start its rant and do you know what by the end of 30mins (and sometimes or 10 or 15) I realised many times that the mind had gotten bored with all the attention it was getting and actually started to drift off and think about other more mundane stuff instead. That is when I realised that that is all that the mind is - it's an attention seeker - that's all - and when this is spotted and realised by YOU then that is the day you will see for yourself that it can be trained to not be seeking your attention all the time.
But all that comes with time and practise.
Don't believe me, OK that's fine - all I ask is you practise and find out for yourself.
Hope it helps