The thing some people don't recognize is meditation doesn't have to be clearing of all thought but can be a focusing of your thoughts and following them as they flow or creating a new flow in them to recalibrate your thoughts.Never stop talking! I love hearing what others do to see if it works. There is so much information out there that I can get overwhelmed. I love having a place to talk, and seeing the information categorized.
On meditation: I see a physical therapist 3 times a week from constant neck/shoulder/back pain I have had for over a year. I forgot what we were working on but she was having me deep breath. We do this several times. She sat down and said my rib muscles do not move and therefore my ribs don't move. This keeps me from being able to do deep breathing. The next first a saw a different therapist because my main one was not working. She gave me an exercise to do deep breathing but was confused because I wasn't sure if I was. I thought I had been deep breathing for years as it was part of cognitive therapy. I didn't do it a lot since it felt awkward.
I do have trouble with meditation. I can ground myself but I can't do it for long time. My brain never stops thinking if I am not busy. I have to sleep with the tv on at night or I can't sleep from all the thoughts. At least with tv, their words can bury mine. I have tried meditation music but it doesn't help.
When I was in the hospital several years ago, me and others went to a mindfulness class where we could sit or lay on mats. Everyone would sleep for the 30-45 minutes.
I used to have problems like what you're talking about and I've grown up with a lot of ADHD friends who were even worse.