Sometimes I feel like I'm under water holding my breath, & when people say "hang in there, this is normal, it gets easier with time", it's like they're telling me to just keep holding my breath. And it's exhausting - holding my breath is exhausting, trying to just carry on through the day while I'm holding my breath is exhausting. I all want is to just be able to come up for air and breath normally and easily like everyone else, and if I can't do that, just let me sink to the bottom and let go.
It is normal. And it does take time. But each time you get yourself through one of these periods, the next one is a little easier, you're just that much better at coming up for air.
Two suggestions to help a bit in the meantime? First, maybe talk to your doc about your meds, tell them that you don't think they're helping. I just started a new antidepressant for the first time in 2 years, and just the hope that it might help just a little has made it a bit easier to get through each day.
Second, even though you probably don't 'enjoy' anything (anhedonia is part of the depression), try and do something each day that you might have enjoyed once, before the ptsd, and do it mindfully, without any expectation that you'll "feel better" for it. I make a point of spending quality time with my guinea pig, Oscar, each day. Most days, when I put him back in the hutch, did I "enjoy" it? Nope. But I was cuddling him mindfully, focusing all my attention on the little ball of fur in my hands. And even if it didn't make me happy, I know that for that 10 minutes, I wasn't feeling overwhelmed by my emotions, I was just breathing normally, without the struggle. Acknowledging that, that I got 10 minutes where it was easier (not happy, just breathing), helps me get through my day. Every now and then, I actually do enjoy cuddling the little fella, and I know that some day, I'll be able to enjoy it every time. In the meantime, I pull him out of his hutch whether he likes it or not, and I just sit with him mindfully, and he helps me to just breath.