OP, FWIW I see a lot of me in your post, me at my worst after my first miscarriage which traumatised me for many reasons. I then went on to have two more, now pregnant with my little boy, 33 weeks. 2.5 years of hell. Also a senior role in work. I'm also the planner, organiser and scheduler by nature and definitely take upon myself more than I should because DH is horizontal, not even laid back. Also doesn't fully get my concerns or emotions because he's an optimis whilst I'm a realist, and also an anxious planner for the worst, just in case.
I never attempted suicide, but at my worst I genuinely thought if I trip over now and fall in front of that train at the main station, things will be easier for me and everyone else. I felt so shit that I didn't want to be here. I had a constant chain of thoughts in my mind, my mind was racing and never resting. My body felt physically inflamed with exhaustion. I became insomniac. I was constantly rushing, threw myself into a number of huge projects, kept busy with my appearance, planned every second of my life way ahead and NEVER rested or enjoyed my life. At all, in fact. I took no pleasure from seeing friends so I avoided them. Never did anything that normal people consider nice with DH.
After about 5 months I was so burnt out and exhausted that I couldn't cope. One day I had some difficult news over the phone from my friend and I broke down. I had to take time off. I went straight to counselling, privately, because NHS dismissed my concerns about the state of my MH.
I am telling you this because talking therapy was a great help to me. It was my time to open up and let go of all the burden, heavy thoughts and emotional difficulties I was going through. For some reason I felt that I had to run away from them by keeping constantly busy. This strategy seemed to have worked for a period of time, but in reality it led to a complete burn out. It very much sounds to me like you've turned into what you're doing even more than you usually do because it gives you the sense of comfort, control, familiarity and inner peace. However, this comes at a cost to your body and mind. There is something under that lid that you need to let go off first. I'm so glad you're going to have therapy and I hope it really helps you. FWIW, I thought mine was doing nothing for 2 months, but then suddenly I realised I was able to actually take a break. And rest again. And then started enjoying the smaller things in life again and have some positivity. I've realised my life was taken over by grief and massive anxiety.
If I'm honest, the latter didn't completely go away, but it's now managed better. The former has become my companion in time, not welcome, but accepted, and that's ok.
Sorry if I'm off the mark here but your post has really struck a chord with me as I could have written this myself 2 years ago and frankly it would have been my desperate cry for help because things weren't right, but I didn't know how to fix them.
You're doing all the right things now. It will take some time to be more balanced again. What also helped me greatly was learning to meditate, acupuncture and reflexology. I cannot recommend them enough, but together with your therapy, not as a replacement. I ultimately took on jogging and drawing too and these new activities helped. But I did this after I recovered more energy first. Your mind and body need to come first and reenergise - you are the most important 
. Best wishes to you & take care xxx