AC problems on my 2009 honda civic ex

Ok so I turned my A.C. on for the summer and it
works for about 5-10 min with cool (Not cold) air
and then starts blowing warm air. I asked my friend
who works on cars and he said it is probably low
freon. As he recommended I bought myself a 20 oz
can of ac pro and plugged it up and put it in, while
putting in the freon it didn't really change the level
on the gauge which I found weird. But the ac
worked amazing while putting in the freon. The
next day I had the same problem with it blowing
warm air. So now I am trying to figure out what is
the real problem. I just checked it this morning
while the engine was cold and parked the ac
worked great. But after driving to work (about 15
min drive) it was going warm again so I popped the
hood and watched it cycle with the ac on. The a.c.
fan came on and the comoressor would shake to
start up but then immediately cut off. I don't know
what's going on with this I have read a bunch of
blogs and have a bunch of ideas. I would rather not
bring it to the shop and pay a bunch of money if I
can fix it myself, but I am about to cause I can't
figure it out. I hope someone can tell me what's
going on and maybe a way to fix it.