Oh I'm really feeling for you, it sounds as if you feel both 'stuck' and overwhelmed.

Desperate times call for desperate measures. You may need to make some tough decisions in order to wrangle your life back under control. That might mean considering home-based child care or a shared babysitting arrangement just to give yourself a break, or finding a counsellor so that you can debrief and start to heal the traumatic experiences you have had. That might be someone with more of a spiritual bent than a regular psychologist, kwim, or even talking with your doula? You may need to discuss antidepressants with your dr or even just to hook into some sort of support service that might be available in your area.

Re the stroller, have you tried to introduce it by just keeping it in the room so your DD can see it, touch it, etc and get used to it for a little while, then try her in it for very short periods when she is well rested and well fed and engaged with a toy that she likes...lots of tiny short exposures might help her get used to the stroller, kwim? We had problems with a new bath that we bought for our DD and did this, just let her have it near and see it and eventually play with it, before sitting her in there for short periods in the lounge room where we spent most of our time, with lots of happy noises and encouraging facial expressions. It worked and she was quite happy to go in the bath after about 10 days. Might be worth a try...?