I have GAD (Generalized Anxiety Disorder), PTSD (Post-Traumatic Stress Disorder), and I've been diagnosed with PMDD (Premenstrual Dysphoric Disorder) and PPD (Postpartum Depression).
Have I "beaten" them?
I'm considered fairly well managed. I live in California and have a medical Marijuana card. My husband calls it my "apathy enhancement drug". I started using pot *after* I had kids and ran out of Western meds to try for anxiety management. I feel sorta evangelical about the substance. My life is so much better than it used to be. I can make forward progress on areas of my behavior that I have not been able to in the past. I can be calm and "in the moment" in ways I have *never* been due to my extreme hypervigilance.
But I'm coming off years of extreme self-harm. For me, pot is a much less extreme choice than the things I used to do to manage stress. I can get edibles so I don't have to smoke (though I sometimes choose to do so).
It isn't a path that works for everyone. There are lots of reasons that it isn't ideal. It isn't legal everywhere. It has negative health side effects.... just like every other medication. I draw comfort from the fact that unlike most other medications that I have been given by doctors it is just about impossible for me to overdose on pot (no recorded fatalities *ever*). Given my overdose history I like ensuring that there is no chance that I can overdose on the amount of medication in my house on any given day. It would be annoying to have a daily med I needed to get from a store that often.
So! OP, first step: give yourself a long line of slack. The first year of having a second child is going to be really rough. Steal yourself to kind of hold your breath till 18 months. Then it often gets a lot easier. Feeling overwhelmed isn't a sign that you are failing. It is a sign that you are in an enormously overwhelming period of life. I spent a lot of time stealing a few minutes in the bathroom alone so I could chant, "This will end. This will end. This will end." Some days were rough.
My kids are 6 and 4. Things are much, much better. I take a lot of time for self-care. I have a husband who understands that I need serious support. He does almost all the cooking. He is on duty with the kids when he is home. I am *not* the main person to ask for help at all hours of the day. Just, forking no.
I have a trusted babysitter. She is here 4-8 hours a week. She's a local home schooled kid who is available during the day. She is saving my life.
Looking for support is really hard. But we all need support. That isn't a sign of your failure. That is a sign of your humanity. It is signaling that you need to depend on your community somehow.