Thank you for your inputs. I have an aunt that has been living with fibromyalgia for 20 years, and she's got sjogrens and other health issues but not cfs. So, I guess that fibromyalgia runs in my genes.
I understand also that the main symptom in cfs is PEM, but I'm not sure if i have that one. Let me give you an example and you could tell me if this is PEM: one week ago i went to Moskow to visit a friend, the first day that i arrived i was able to rest enough, but the second day she took me all around the city, and she made me eat gluten because her mom had cooked a very special meal with soy sauce!
Anyway, that night i went to bed around midnight, i sweated all night and i couldn't get up until 2 pm the next day. Then i got dressed and went out until very late. The next day i was out all day without problem, and the day after that i travelled from Moskow to UK without any issue. Yes, when i arrived i was tired but not exhausted. Also, some days the temperature dropped to -16 degrees and even though i'm not very fond of the cold weather i was able to resist.
So, the fact that i couldn't get up after a busy day and eating gluten is PEM? If not, when must i expect to get PEM?