Perry, this isn't depression, you are just upset with your mom. Depression occurs for long periods of time and can severely disrupt your everyday life - sometimes even resulting in suicidal thoughts or suicide itself.
If you mother felt the need to take your phone away, I'll wager you were rude to her when asking about a sim card (you yourself admitted that you stomped away as soon as she said no, did you slam your door as well, or yell?). Be patient with your mother - she's certainly trying with you! Raising kids isn't easy, especially when children are at an age where they refuse to appreciate what their parents provide for them (For the record, I didn't get a cell phone until college, and only after I'd had a job long enough to afford one! Parents are obligated to love, protect, shelter, and feed you. They aren't obligated to cave to your whims and buy you things you want but don't need, especially if you have an attitude about it).
You might roll your eyes at all this, but when you're older, you'll understand.
If I lived in Ponyville, I'm pretty sure my cutie mark would be a taco.