Headaches are not bad, nor is occasional blurred vision - this is your pituitary gland growing as it tells the body to get ready to lactate (produce milk). If you had a brain scan it would show that it has grown quite a bit, but because your head doesn't grow with it then it starts pressing on various bits of the brain and the optic chiasm, so your vision may get a bit worse. The headaches will go away once the brain is used to what's going on and your gland will shrink back to "normal" once your baby is weaned.
Wow, never knew that!!

I get headaches too and don't think I've put on any weight although I do have a bit of a belly now. I don't normally weigh myself, but I'm almost certain that I lost some weight as I am still under what I remember being the last time I weighed myself which had been a long long time before. Not sure if I lost it before pg or with m/s and not feeling like eating too much.