L.C.
Sometime during the time my son was 2 he also went through a phase where he would not allow me to brush his teeth. I forced the issue which did make him cry (I told him he had to). This only lasted a little while. He turned 3 and we really don't have too much of an issue anymore. I still am the primary when it comes to brushing his teeth. I asked his dentist and they suggest I continue to be the primary one to brush his teeth to ensure it's done well.
It's probably time to think about going to a pediatric dentist and the one thing that really helped me get through this stage was to take him with me to the store to pick out a toothbrush he wanted. At the time it was a spin brush with a fire truck. We use battery opperated ones. The biggest issue with those is getting the ones that they can easily turn on. The fire truck he couldn't get on, but it did greatly improve brushing his teeth.
Good luck