depo shot

I went to the doctor today and asked for birth control, I was leaning towards the pill but the doctor inclined me towards the depo shot considering I am a college student and she claimed it would be easier since the pill I would have to remember to take daily so on and so forth. I obviously complied thinking she's a doctor and should know what she's talking about so I got my first shot today. I came on here to hear thoughts about depo and now I'm terrified, I think I made the wrong decision and there's nothing I can do😔 I read that you bleed for weeks at a time and I just can't bear the thought of that. All the doctor said was that side effects would be having my period, spotting, or not having it at all, regardless I thought it was ok all good. Now I'm scared, what should I expect? Man all I wanted was to not end up being a mama at my age...