If you feel bad about UC results so far...
I am a 9th grade dropout (was pretty much forced out of school as a punishment), escaped a cult as a child, loads of mental disabilities (the trauma kind), etc etc right. I don't say this bc I want sympathy (pls dont its awkward) its just context right...
I literally self taught all of high school (and frankly middle school) to myself in like 3 months, enrolled in to a CCC, spent two years grinding through classes to become an applied mathematics major, etc. 3.6 GPA, pretty much nailed all the reqs except for some like DiffEq and Linear Algebra. First Gen College/STEM Student, etc etc...
Not gonna cover all my EC's here but I've accomplished some pretty insane stuff in my life despite all the setbacks, they were stacked, like top 0.2% stacked.
Got absolutely slaughtered so far in UC apps lmao, UCI broke my heart for a good 30-60 mins (was missing Linear Algebra for Quantitative Econ major w/ applied math as the backup)
UCSC did accept me though <3 and so I am pretty hyped about it. Mentally ready to watch the rest of the UCs reject me (applied to all)
Keep your head up y'all, this stuff can be a total lottery. Do not let a number or a rejection define you. School prestige helps, but there are very few and rare fields where it matters beyond what the words on your degree say. Even then that sort of a entry level issue.
Also do remember if you are trying to get in a field where prestige matters, the prestige of your grad school can completely override your undergrad, and its often much easier to get a higher GPA and research opportunities at a lower ranked school.