imessage gets stuck on 90% sending on ipod touch 5g

My ipod touch 5g gets stuck sending messages on imessage, the sending bar goes to 90% then stops, and then after a while it says 'not delivered'. And during this period facetime doesnt work as well. I can sometimes use imessage and facetime but most of the time it doesnt work now.

I already tried rebooting, turn on/off wifi and imessage, nothing works, how do i fix this?

my wifi works fine with safari, youtube etc btw