2010 Yukon a/c problems

[Peyton]

Hey guys, new to forum, looking for some help, my wife has a 10 Yukon, she has been making comments to me about her air not blowing but I never could find an issue, when she would get home she said it wasn't blowing anything and I would go outside and crank it up and everything was working fine, so I chalked it up to her pregnancy hormones!! Haha but we loaded up yesterday to head to the beach and made it about an hr down the road and I noticed it was kinda warm, turned temp down a little and put my hand on vent and no air was blowing, turned temp all the way down and you can hear blower running but no air coming out any vents, turned it off let it thaw out thinking it was frozen up and sure enough after 10-15 minutes turned back on, blows ice cold, then after while freezes up again, I thought low on freon I will buy one of those el cheapo cans with gauge and gas it up and be done till we get back home and find real issue, stop by Walmart pick one up, get to where we are staying put gauge on it, pressure shows good, not low at all maybe even a little high? Little hesitant to trust cheap gauge and all my tools are 300+ miles away and I have a return drive home Sunday with a 4 year old and a brand new baby! any ideas other than the freon? or how trustworthy I should be of this gauge?? Any help or ideas would be greatly appreciated, I'm pretty mechanically sharp but I know nothing about ac systems

 

[Ex Euro Driver]

I'm confused. Does the air stop flowing completely or does it blow cold then warm air?