i'm thinking of applying for ssi

I have to cut more hours from work because its making me so anxious i am getting dizzy at work, (I work with kids and I got so dizzy to the point where I had to sit down for about 10-15 minutes at a time, and even then, I was still dizzy and faint) and my supervisor today said I cant "constantly change my hours"and that if I "cant commit" to the schedule I'll be put on the sub list, but i need the money but i honestly cant work anymore hours even though im only working a few (15 hours a week)

im just scared because i hear everyone gets rejected the first time and that its a lengthy process i am moving to a new state in a couple of months and i'd only need it for a little bit while im still in this statei really need the money, especially now that my boss gave an ultimatum i cant commit to the schedule but being a sub means i may not get the hours i need to afford food or clothes, i can barely afford them now as it is, and yeah, i do get some help from my parents, but they don't make that much either. i still live with them, so i worry that may be a strike against me for getting SSI

i am also afraid of what my parents might say, they may say i am not disabled because i only have mental health diagnosis and my physical health is okay, but work has been way too stressful for me, my symptoms are coming back pretty strongly and i have been
to deal with the anxiety.

i don't need a lot, just enough that i can maybe go on the sub list, or work fewer hours but still get enough money coming in that me and my bunny can eat.

i'm looking for some information on the process and what things i will need, i am also wondering how long does it take to apply? i kind of need the benefits soon.