Depends what your motivation is for getting it done. I hated my subject so just treated it like a job. Procrastination is completely normal, you just have to get on with *something* most days and it will get done. GOing over 4 years is very common, it just means you have to dedicate extra effort when you're working full time AND trying to finish it off.
I very much doubt its giving you migraines - have you had your eyes tested? Otherwise you're just stressing yourself out with it, so you need to consider relaxation techniques or getting out to the gym every day or something.