0.5% for employee #1 is very low. Sounds like the company is doing well, and also that you're in-demand in the industry, so if I were you I'd use these facts to

0.5% for employee #1 is very low. Sounds like the company is doing well, and also that you're in-demand in the industry, so if I were you I'd use these facts to try and negotiate a higher salary (I wouldn't value equity too highly). If they don't go for it then I'd be ready to take another job — you can definitely get a better package elsewhere (FB etc), and it sounds like you're not super satisfied where you are right now. Compared to founders, early employees get a bit of a shitty deal in general, but your equity is definitely below market rate for a first employee. All the best!