I don’t know if you already practice meditation, but there are a few threads on here with links to guided meditations as well as posts to read through.
https://talkingsober.com/tag/meditation
I don’t have experience of PTSD but there are many here who do. If you use the search bar 
you might find some helpful stuff.
Also the mental health memes thread is a lovely and wholesome place to hang out here.
Of course this isn’t intended to replace medical advice but that isn’t what you’ve asked for! Hope you find what you need to help you through 
