Glad you're OK. Sounds scary. Get checked by a doctor anyway since you took the blow to your head. Neck and back problems could arise later. Is the bike OK?
Hopefully you got the guy's insurance info, truck company name, truck number, etc. Don't let it slide. Make the company pay for damages, hospital visits, whatever. Most trucking companies don't want the bad publicity for their drivers' actions and will work with you or your attourney.