Main goal of CO2 is to fix your flat a little faster and get on, forget about actually pumping it up to your normal pressure get in what you fill is needed to ride on for now.
CO2 will be deflating by the next day anyways if not almost flat again, remove CO2 air and pump it back up with your floor pump when you get back home.
I guess you can over inflate but that depends on what size tire you are using it on and CO2 size, your more likely to burst your tube because the tire is not seated correctly.