I was rejected from every UC (didn’t apply at UCM or UCR) and waitlisted at UCSC too! I truly thought I would get into at least 1 good UC. I’m still waiting for UCI and I was waitlisted for some privates but I am not hopeful for them. My gpa is 3.7 and 4.0 weighted and I have good extracurriculars, but what is done is done I guess.
As one high schooler to another, I recommend only trying to cram in all of your CC classes into 1 year if you are sure you can get good grades in all of them and have strong extracurriculars on your new application when applying to college again. BUT this only applies if you are not going to do TAG.