This is just my second mc, the first was 8 days and this one is only 10.
I have experienced some emotional upset as well though will cleansing, namely a child custody battle and highly irregular periods (4 periods in 5 weeks). For me, this is about control- control of what I do or don't eat, control of my weight problem and just control in my life- period!
The Master-Cleanse gives me something else (besides the negative) to focus on and gives me a sense of control that is lacking in most other areas of my life. I believe I've read how much better for you a long fast can be, but I'm just not there yet.
I'm not sure if you're spiritual at al but pray about what's troubling you, develop a 'mantra" to try and help pull yourself out of the depression, maybe even develope a hobby (I took up knitting) and keep fasting 'til you feel like you're done- only you will know when it's time.
I hope this helps if even just a little bit. You'll be in my thoughts...