I hear you. A few years ago, when I started on MFC, I was going through a very long and dark depression. Most days I couldn't even get out of bed and it made camming really hard but at the same time it was a great option for work. Whenever I got online and had fun performing and interacting with others I completely forgot about my depression. The getting online was the hardest part though. I suggest putting on some happy and energetic music, dancing around or singing along, just to relax and get you in the mood. The worst thing for me was and still is getting too comfortable when things get tough and then losing my momentum - I'm not in my "flow" anymore, which is always harder to overcome the longer you stay there. So try not to take too many consecutive days off and try to stay occupied and active during your days off (go outside, move your body, do whatever brings you joy).
Apart from that, I also suggest a good support system where you can share safely whatever you're feeling. Eating healthy, exercising regularly, regular sleep and enough of it (can't stress this enough), plenty of fresh air and sunshine as well as working on balancing your emotional and spiritual life as well. Good relationships are also essential. And try not to be so hard on yourself, especially on a bad day or even a bad week/month...sometimes the change of attitude/state of mind works wonders. So, in a nutshell: try to find joy and fun in life and activities and just go for it.
The more you practice this, the better you get at it and it becomes a new normal. Sure, it's not always as easy, especially if you have chronic conditions...but only until you start to have fun and get in the zone.
It might help having a cam girl buddy you can be accountable to and you can share challenges with as well.
Good luck!