Does switching majors look bad for graduate admissions?
TLDR: You should switch majors
Engineering (of any kind) is hard. If you are excited about it and love it, then putting in the work is possible.  But if you hate the classes, you are going to find it very hard to be motivated enough to do the work needed to get As.
And you do want As for grad school. One bad semester won't kill your grad school chances.  Four more bad semesters in a row will.
Either Electrical or Mechanical are both good starting points for BME (just as good as if not better than Chemical).  Pick whichever you suits you best and switch.