My knees are very messed up?

heyy :-) well thing is the past couple weeks my knees have just failed.. its been more on my left one but ive had almost like grinding pains when i walk, to feeling like theres water in there, to them just going completely like jelly. I had a beep test thing last week in p.e which didnt help anything, my knees were hot and shaking the whole day! i really want to know whats going on, im not at the doctors till 2 weeks on monday at the earliest though so any ideas are appreciated!.. Oh, and im very hypermobile in my knees, i stand sorta funny cos they go right back so my legs look curved.. could this have like.. brought it on? hmm.. thankyou guys!