Why am I having toothache while chewing with filled teeth?

Hello doctor,

I got 6 fillings done a while back that were causing me no pain whatsoever or sensitivity, so I found a new dentist got the filling done and by week 3 the fillings on the left top were causing me more severe pain than week 1 and my bite was off no matter how many times she adjusted it there was only 1 tooth touching and being damaged, dentist is denying she did anything, says there is no infection.

I finally went to the ER and dentist visits later and I had an abcsess lanced on the roof of my mouth and need a root canal on a tooth that had a short cavity in the first place by the dentist, the pain goes away with antibiotics and I have been doing alright for the past 2 months except pain when eating on the effected side, now all of sudden the top 2 molars on the left where the infection was there are red around them and pain when pressure is applied. Mind that when I bite down on top left second to the back molar is the only tooth touching anything all the others are not touching each other no mattter how hard I try since my dental work and I am scared I am getting an infection again.