1999 Ford Expedition it just wants to go nite nite

For a week now, I thought something was tapping into my battery while my poor truck slept in the driveway. I would go out in the morning to go to work, not consistently, and the battery would be dead enough to where it wouldn't start.
i have a jumpstart, so I used it. A total of 5 times over the last 7 days.
once it starts, runs like a dream. I love my truck. So, 2 days ago I noticed that I had to jump it, then I parked about 10 yards from where I would have liked to park, but when I went back to move it a scant 15 minutes later. You guessed it, it was dead. It got to stay where it was that night.
then, I noticed a a weird clicking noise. Like on the inside, driver's side I spose, kinda like a blinker noise, cept more spaced out. And get this. When it goes 'click' my interior lights come on, and 'click' again and they go off. Then the whole thing stops clicking or turning on. And I come to realize it is napping again.
yesterday I pulled into a parking lot, and it DIED. Now it won't start, with my jumpstart or not. I replaced a fuse or few, I am trying to start cheap and work my way up, but if you know what the issue is, PLEASE save me the trouble. I am a short girl and it is damn cold out there!
thanks.