Can someone please tell me if they think this sounds like depersonalization-derealization? I'm really desperate to hear someone's opinion!

I've been having the feeling since I was really little. I remember the very first time... it was accompanied by really bad lightheadedness and tinitus (ringing in the ears), and I felt really sick...it was the scariest thing I'd ever felt. Over the years it happened less frequently and also got easier, but now it still gets bad. Whenever I think about it it comes back, so of course I have it right now. The worse it gets the more confused my mind gets and the confusion is so scary. In the beginning, whenever someone talked it seemed weird and alienlike or something (I'm not saying that I was hallucinating that the sound was different in any way), and for some reason I'd have this fear that I wouldn't be able to think or communicate but I still could. It felt like I was in a dream or something. I described it like "I knew I was there but I felt like I wasn't" or "it looked like the world around me wasn't real but I knew it was" I used to think I had some kind of rare mental disease or something, something serious. There are many more things to say about this problem but I'll start with that and see if it sounds familar to anyone...
And now it's getting so bad I'm starting to find it hard to concentrate.