i went lvl 32 a week ago an then i logged on the next day and found out i was lvl 55 :/ i thought: "ok no problem, nao i have better weapons anyway" but no... i dont have the weapons. only lvl. than i took a quick look:
current lvl: captain 32
next lvl: captain I 33
EP to next lvl: -831232( !?!?!?!? )
sby knows how to fix this?

Wtf .. thats clearly the same glitch as me ..
You have got to delete your save file and make a new one .
If you want to get it fix try it .
Cuz mine is fixed .

i dont wanna lvl up all again :/

Neither do i .. but if you want it fixed do my advice ..
OR contact infinity ward support to have it fixed .
What console are you using ?

uhm pc? xDDD

What ?
xD . then take my second advise .
Contact Infinity ward support .
Hope it helps