Have you always been injecting it? Maybe our body just doesn’t work with it…
I’m not a medical professional but I could see a case where your body processes your injected estrogen too quickly leading to big and constant hormone fluctuations. Don’t really know too much about what that would do to your body but it would make sense for your psyche to suffer a lot from it.
Edit: if you don’t want to / can’t get pills, you could try doing 1/4 your current dosage every other day and see how that turns out (if it’s even possible with your type if syringe (DON’T REUSE THEM!!))
What about patches or gels? From what i’ve heard, patches seem to be pretty reliable