Just got back from the Hospital

So two days ago I got back from the hospital where I spent two nights and three full days. I got diagnosed with a bad concussion and I can't walk that well because I'm so dizzy. Also I can't go in cars without feeling SOO sick. There are other stuff that's wrong too but m not going to name every thing. The thing is though my grandmother just died and she lives in a different state so my mom wants me to take a flight out to there for the funeral and I told her it would be like torture going on that plane it's too soon after my accident. She got REALLY mad and started to put guilt on me and made me cry. Then she started to say stuff like she's going to make me quit soccer if one concussion made me feel this sick (even though the doctor said I can still play). But the real reason she said she was going to make me quit is so I push myself to go on that flight. I just don't know what to do or who's right in this situation. I'm 16 by the way.