As someone who's primary community consists of abuse and recovery victims of varying ages: moms behavior has red flags all over. Whether or not she's doing it consciously, that is an invasion of space with intent to gain control over her grown adult kid. I had more respect and autonomy at 16 than what this person who has apparently successfully completed at least one round of college is being given. So yes, having someone invade your space, touch your things, and endanger the well being of your pets is grounds for being upset, and I would say justifies venting a little.
pffft! this...this right here is why kids want a "safe place" to run and cry if it rains too hard...we equate moving a mirror to mental abuse...
OP can hash it out with their mom offline, if they can't get along, OP can move out. Its that simple. Come on people...