Is your hotend still heating as before ?
Did you check that the dents which grips the filament (hobbed bolt or insert) are clean of plastic ?
You might want to disassemble your hotend and check that nothing is stuck in the filament way : thermal barrier, metal barrel...
You can try and push a piece of filament by hand in each piece to find where is the problem.
Also, this is not the best place to post this problem, you might have more appropriate answers in this section : [
forums.reprap.org]