2001 Ford Expedition Eddie Bauer Major Starter Issued

Had some issues with my truck so.. I changed the
alternator fuel pump fuel filter and a gas hose. It
was up an running again not the greatest tho well
went to the station  come out and my truck
wouldn't start i had power just wouldn't start i don't
recall what type of noise it was making but if any
but I happened to remember about this little truck
my brother told me about many years ago but I've
never done it he explained but that was years ago
well luckily when I was about to crawl up under
there one of my husband's friends from work come  
out an asked what the heck I was about try an do
he knew what I was talking about so he climbed
under there an tapped on my starter with a wrench
an my truck fired up if I'd drive it for a while it'd
typically stay running but every time you shut it off
you knew there was always a chance it wouldn't
start again until you got back up under there to tap
on that starter again well it started becoming more
frequent that this was accruing well eventually i
became to pregnant to be climbing up under there
so one day I just kept it parked when it didn't start
again one morning right now my battery is dead
due to sitting battery less than year old what do
you guys think is wrong with it I'm about to try an
order a starter but I need to have some type of
reassurance that my next move is the correct and
hopefully my last move with my truck oh an I never
noticed an codes either gonna air my tire up and
try to get it to jump and see what happens from
there any advice is appreciated