Dear sir/Mam, I understand your problem.Every tooth has three layers .The third innermost layer has nerves and blood vessels.when the tooth decay is progressing in first two layers we will not have pain since they dont have nerves.When the decay enters the third layer , it damages the nerve and blood vessels.These decayed tissues will develop pus.This infectious pus will not have enough space inside the root canal.so it spreads up through the root tip by resorbing bone.Thus there will be bone resorption and pus collection around the root tip.Thats why you feel loose and painful when you chew something since you increase the pressure inside the pus collection.when the pressure from pus collection keeps on increasing , it will keep resorbing the surrounding bone and comes out as swelling of cheek.so permanent solution for this condition is to clean the pus filled tooth with root canal treatment.If you are not affordable at this time atleast take some antibiotics like cefixime 200mg twice daily for 5 days to control the pus collection.But this problem should be taken care of before 6 months(maximum) to prevent loss of tooth and bone structure. Hope your query is answered.please dont hesitate to contact back for further queries.