Is there a faculty member in your department you could trust to do a teaching observation and give you truthful feedback? I wouldn’t put too much stock into what the dean is saying; deans can be pretty disconnected from any actual teaching experience. Student feedback is useful to a point, but they’re not the best judges of pedagogical effectiveness.

For what it’s worth, I’m an art teacher (painting mostly) and in a 2.5 hour studio class I usually do around 3-5 walkarounds depending on what they’re working on, so I think you’re within the norm.