Hi Teddas,
When I am in one of these slumps and I can't get out of bed, I find it's helpful to have a process, either in your head or written down, for the things your body would normally do automatically.
Your goal is to get to work, so what are the steps you need to take to get there? The more overwhelmed you feel, the smaller the steps. So this might be:
1. Get from the bedroom to your wardrobe.
2. Put out your work clothes on the bed.
3. Get from the bedroom to the bathroom.
4. Take a shower.
And so on. At each stage, try to concentrate totally on that task until it is completed and you can move onto the next one. Once you are at work, sit down and plan out your tasks for the day in a similar fashion so you have things to concentrate on according to your calendar.
Aside from that, it sounds like in the short term you also need to have a plan around managing your contact with this woman so as to minimise your distress. How closely do you have to work with her?
