sertraline?

I am supposed to be taking sertraline to treat my ocd, anxiety and depression. I really don’t want to and I’ve been putting it off since around the start of this year. I am taking it now only because my mum forced me into the hospital a few weeks ago and now they are making me take it. does anyone know much about it? I’m also quite worried about the side effects. does everyone experience them or is there a chance I may not get all of them? and can it cause vomiting or just nausea? it also says on the box not to take if your under 18, I am 14. will this still be ok? I know that the doctors wouldn’t have given it to me if it wasn’t but I just want a second opinion. thanks :)