Hi,
I do not know about taking time off regarding MH issues, but this is my story. Last year I was suggested to take time off because of my health in general. I had a lot of stress because the position I held was with fair enough responsibilities and troubles. In addition to my physical disability, I have PKD. Stress is supposed to be a trigger for cyst grow. In fact, the last doctor before the one that suggested taking time off had told me to look for another job. It is not easy to find another job when you are disabled and a foreign visitor. And, like you, when I was suggested taking time off, I felt my supervisor would not like me taking time off because this would mean overloading for her. In addition, in the institution I work for people do not take long periods of time off usually. So, I did not do it. Then, I had to travel overseas for a long mission in several countries (all undeveloped countries) . When I came back I gota n unknown infection. Doctors could never find the source of infection, but I developed an inflamatory response that almost killed me. I was very sick for around six monts. Doctors told me to call my family and have somebody to come to the US because my condition was critical. And my supervisor and everybody accommodated. I feel that I had pushed myself too hard. My defense system was very low because of my stress and a perhaps silly infection produced an overreaction of my body. Or it was just the stress, because they never found the source.
I think the lesson I learned is that sometimes things get big in my head, I elaborate a lot of scenarios (terrible scenarios) and then I refrain from doing stuff (like taking time off, etc). Then sometimes reality obligues me to take that step, and things do not result as terrible as I imagine and I should have taken that step earlier. I could have died because of the way I elaborate.
OK, I do not know if this is similar to your situation, but I wanted to share this with you. I wish you the best