Ditch the nerd look, hit the gym, and buzz it down, you don't have to "shave" it necessarily. As in, you don't need to use a razor, just an electric clipper with a 1 guard on is fine. Scott Van Pelt looks good bald I'd say but not everyone can pull it off.
If you are cool with that look after, then stick with it, otherwise you'll have to get on finasteride (or possibly dutasteride, which is a more aggressive treatment), minoxidil and nizoral, and possible hair transplants further down the line.
It is possible to regrow hair and thicken up but it will be a daily commitment indefinitely if you choose to go that route.