I'm with Cint: Take it one day at a time. Now, I'm an atheist, so please don't think I'm preaching at you--I am absolutely not. But I always loved this quotation from the bible: "So do not worry about tomorrow; for tomorrow will care for itself." Trying to cope with epilepsy and develop a positive attitude is impossible. Trying to cope with epilepsy and have a positive attitude today is more than possible--if you go about it in a smart way, it's highly probable. I won't pretend to know more than you do about attitude, so I will just say that when you're finding tools in the moment and in the day, you will slowly learn and become better at it until you have a very good idea of how to cope and are coping almost all of the time. When you wake up in the morning feeling dread about how you'll manage 'this', cut yourself off and ask yourself whether you can manage this day, or this minute. In the beginning, and under more difficult circumstances, I couldn't manage the day. I had to do it one second at a time. After I woke up, all I asked of myself was to get up and have a cup of coffee. That's really easy. Then I told myself I could manage a shower, and doing that was easy. And so I went about the rest of the day until it was over. Granted, I was also suffering from a trauma at the time, so the experience was probably more severe because of that.
It isn't necessary or even advisable to feel happy or 'positive' all the time. It's more appropriate and helpful to understand that being positive means feeling everything you feel so that you can pass through those stages in order to get to the other side. There is a reason we feel fear or anger or grief, and these emotions aren't negative ones or a sign of a bad attitude. A bad attitude is refusing to process those feelings and trying to feel great every day. If you can get past seeing some emotions as negative and some as positive, you will have done yourself a great favour. Having seizure after seizure, with severe drug side effects, an ailing income due to illness, and strained relationships due to epilepsy, tends to make a person feel crap. Please don't run around clapping your hands and skipping along.
When you're diagnosed, the appropriate and healthy response is to start a grief process, which helps you to accept and come to terms with your new reality. That process entails some denial (The doctors are totally wrong and I'm not sick at all), some anger, some short term depression...and eventually acceptance. Acceptance doesn't come first. It comes last. So if you really are wanting to have a positive attitude, you will need to get through the grief first.