Hi considering your age pain in teeth indicate decay which needs filling & itching gums swelling ,all indicates gingivitis that needs scaling
Definitely glycerine n sensodyne won't help in such situations
Next Steps
if emergency can take painkiller prescribed by Ur doctor . kindly don't experiment with medicines . consult Ur dentist to confirm diagnosis n then only proceed.
Health Tips
teeth don't repair on their own they need proper diagnosis & treatment.