I was not wearing a helmet. Does that matter?

It depends. If your state requires that bicyclists wear helmets, then it may influence your claim. However, it will not automatically disqualify you from filing a personal injury suit. This is especially true if the driver was clearly at fault. During a bike crash, the cyclist typically has multiple injuries. Even if you were wearing a helmet and protective gear, being struck by a vehicle can still cause great bodily harm.