The first thing you should do if you are involved in a motorcycle accident is to get immediate medical attention. As EMTs, paramedics, and doctors attend to you, make sure they document your injuries in writing, including any referrals for mental health services to help you deal with things like shock, anxiety, PTSD, etc.
You should also make sure 911 is called so you can file an official police report regarding your accident–doing so is key to making sure your case is properly investigated by local law enforcement. Once you have filed a police report, you should hire an experienced motorcycle accident attorney to represent you in any legal battles that follow your accident.