AC issue

Its been about 2 weeks now and i have noticed that my AC is not cooling the way it was two weeks early even though i had freon added to the truck it does not seem to cool as well any ideas. It starts off hot and the cools somewhat after driving it for awhile but i could sure use some help or advice from anyone thanks.

You probably have a slow leak in the system. Get the pressure checked

I agree you have a leak advanced auto has a dye that you can put into your system it works well for finding a small leak put it in and run about 2-3 days the check around use a flashlight look EVERYWHERE sometimes a leak can be in the most remote spot on the a/c system if you do not find a leak check your clutch fan many people dont believe that a clutch fan effects the a/c system but it does it was proven to me (I said no way not possible my boss proved me wrong)