Q: Won't start

For the longest time I jumped my battery with another car, because I didn't drive it too often. Then one day jumping it didn't give it enough power. So then I used a power pack plugged into the wall and jumped it that way. That worked for a while but then that stopped working too. Then only way I could start it was to bump start it in reverse. I decided to buy a brand new battery. I installed it hoping it would start up right away, but it just clicks. The battery is fully charged so it's not that. I had the alternator replaced a year ago. I have a digital volt gauge on my truck and it tells me I'm only getting 10V from the battery. Stereo system and everything works fine, although dims when I try start it. I tried jumping it with the new battery but that didn't work either, still just clicks like there is no power. Any ideas?

My car has 200000 miles.
My car has a manual transmission.