Your issue seems legitimate but has an easy solution. I have had an orthodontic treatment myself when i was 16 years old. So i know it is very easy to be told that these things keep happening and basically to deal with them. The practical problems can be understood by the braces-wearer. Right? So relax, just talk to your orthodontist. They will definitely rase your issue by fixing the problem. You sre doing great. Having braces is a really brave thing to do as the pain and discomfort is unbearable sometimes. Do visit your orthodontist is what i would advise.
Next Steps
Consult your treating orthodontist with the exact explanation of your issue emphasizing on your inability to chew because of the cement as the jsw wont close completely.
Health Tips
Listen to your body and dont be ashamed to ask your orthodontist your concerns even if you feel the issue is small. let them decide if it is serious or not.