I'm sorry you are struggling so much with all this. It can be really difficult to deal with day in and day out...

For me flashbacks most often start as body sensations that sometimes progress to hearing and seeing flashes of past situations, or very out-of-place emotions. The emotional ones are the hardest for me to identify, though I'm getting better at that. The body sensations are the most disturbing and most difficult for me to ground from... I can very much relate to not wanting to be in your body anymore so they would finally stop. I had a very difficult time with that about 5-7 years ago when they started to get very intense. I ended up in and out of the hospital for about a year and a half at that time. I didn't have a trauma t when it all began, which made identifying the flashbacks difficult... once I found my current t, she helped me put words to the experiences. She also had seen reactions to trauma that were similar ,and was able to help me advocate for different treatment at the hospitals when the doctors just wanted to write me of as psychotic (you'd be surprised how many medical professionals believe flashbacks and ptsd only come about as a result of war, and that all flashbacks look like the ones depicted on TV)... I'm slowly learning to sit through my flashbacks or find other ways to tolerate them while working on their roots in therapy. (Though it might be taking me a bit longer because I moved away from where current t practices for 2.5 years. In that time, I didn't have steady or trauma-focused therapy. Now that i'm back to the former t, I'm working on stuff once again... I also ended up with more flashbacks and trauma memories because of the move back to where much of the trauma originally happened)...

I had once found the blog of a trauma t who explained it all really well. He had his own trauma history coupled with a lot of study and work in the field. Unfortunately, he's since given up blogging and the blog is gone... he had written really well about flashbacks and their various forms. I wish I had printed out that post when I first saw it. It was the first time I think I had seen someone other than my own therapist explain flashbacks and trauma in an accurate and understandable way.

As Trace14 suggested, therapy with or without meds would likely be helpful. If you don't already have a therapist, finding someone who has both experience and competency in trauma work would be good. It might take a while to find, but a good therapist can make all the difference.