How can I cope with seasonal depression / anxiety / Post Traumatic Stress Disorder ?

In spite of other problems I’ve mentioned, I was diagnosed with PTSD some years ago. PTSD or not, memories and emotions can be overwhelming when triggered,

As much as I hate the heat and humidity and have problems coping with it, a sudden drop in temps to about 60 f (16 c) has triggered a painful memory / some emotions so intense that I sit here totally dysfunctional and scared. I just keep swallowing hard,

This is not related to being a victim of violent crime which got me permanently injured and on disability—except to say that I don’t think my SS disability will last forever. The memory is related to when my girlfriend became homeless, and I, who was living with my parents due to being unable to work because of the aforementioned gunshot injury—was struggling to provide for her.

My mental state isn’t that good either—I was on Adderall for many years due to ADHD but gave it up when I was unable to work (again, due to the gunshot injury), since I didn’t need the focus / concentration abilities), Now that I might LIKE to try work again, I am disorganized, live in perpetual daydreams or in the past, can’t keep up with things, and a pretty damn slow learner. None of the healthcare I am assigned to will prescribe Adderall, even though it worked wonders for me, being able to really “see” what I was looking at or working with, and desire to organize my chaos.

I am not sure I’d be able to work due to the ADHD being more intense without the medication. I’m afraid of getting OFF disability because of the health benefits and income, although even THAT income is not enough to make ends meet. And I may not be able to get disability again anyway when it is up. So I dread the future, when life slips back into chaos and I have no means of support.

I am able to drive and help my aging parents, who are about 80 and both with failing health. I share an apartment with my girlfriend but cannot spend much time with her because of the needs of my parents. She is in some ways worse off than me, because she has severe depression, living on disability, without a car.

So, where can I go from here, and how do I cope with such intense anxiety, grief, and fear?