School trouble

My son is 6 years old.  He is in first grade and goes to a life skills classroom.  We loved his teacher from last year.  I felt that he was really learning and growing.  She was supposed to be his teacher again this year but during the summer she left the school so he has a new teacher.  I have been feeling uncomfortable with this teacher.  I chose to put my child in the life skills class because all of the other public school options said that he would have to learn at the speed of a regular classroom.  He is unable to keep up with the typically developing kids his age when it comes to learning.  The life skills classroom is supposed to teach him at his speed.  However, with this teacher, I feel that he is being taught at a much lower level.  I am under no illusions, my son is intellectually disabled, but I still want him to be pushed to learn as much as possible and be as educated as he can be.  To be fair, I am in school as well and I haven't been able to stay for a whole day or anything to see what exactly they do.  The teacher sends me notes saying what they did that day and although there are times that she mentions one or two academic areas, most of it is popcorn parties, PE, recess, etc.  I have been there for the last hour of class (once), last half hour of class (multiple times) and I have not seen them do anything but watch an "educational" video in that last hour.  This worries me to no end.  I have been trying to figure out what I am going to do.  I don't know who to talk to, what my options are, nothing!  So while I was trying to figure out my next step another problem has arisen.  My son has had 3 accidents (wet his pants) while at school this week.  This is REALLY abnormal and we haven't had any trouble at home.  When I have asked him about it, he says he is embarrassed, frustrated, and mad.  When I ask why he didn't go he says he was scared.  If I press he says he isn't afraid of the bathroom, anything in the bathroom, or anything on the way to the bathroom, he says he is afraid of asking to go to the bathroom.  This has never been a problem in the past.  By this point, I spoke to the interning principal.  He said he and the actual principal have been spending every day, almost all day, in her classroom this past week to "support the teacher and help her get started".  Something that felt wrong and threw up red flags for me because it is a month into school.  Shouldn't they have done that in the first week or two?  Have other parents complained?  Throughout the weekend, as I have pressed further, my son started crying and saying "bo" (sound of a gunshot, and his name for his Kindergarten teacher, Mrs Gunn).  I have asked him if he wants to get another teacher but he pretty much says if he can't have Mrs. Gunn, he doesn't want anyone.  I don't know what to do, who to talk to, and what my options are.  I am sure that this teacher is a perfectly nice teacher, but I do not feel she is right for my son.  He needs someone he connects with better and someone who will push him to learn.