Buy a book on speedreading. It will very quickly solve the problem of backskipping (which seems to be your biggest problem), will shorten the time it takes you to get through material, and will allow you to retain the maximum amount of information, and understand it better.
Your main problem appears to be not a lack of understanding, but a lack of concentration. Even if you aren’t interested in reading extremely fast, the techniques used to read fast will force you to stay focused on what you read, and this will probably solve 95% of your problem. An Evelyn Wood book is a good place to start.
Sometimes, I find it’s like, impossible to read anything. Like, if something is like several long paragraphs long, I’ll get lost within them. I’ll just forget which sentence I’m on, forget what I just read, have to start over, and end up reading it all only to finish and realize I have no idea what I just read.
I guess it’s like reading something in another language. I can read the words, but once you’re finished with them all, I don’t know what they meant.[/quote]