Traveler was right , usually low on freon, look for hose connections that
have a oily residue,
Check if the clutch is oily etc.

Have a a/c mechanic pull a vacuum and if it passes add dye and freon  and
check after a few days/weeks

First thing ro do is realize that you cannot diagnose AC concerns from only
low side pressures.... Your low side pressures aren't doing anything
abnormal. What is abnormal is the rapid clutch cycling times.... and the
most common (but not the only) cause of rapid cycling is a low refrigerant
charge...

The correct way to proceed from a proper diagnosis of a low charge (using
both high and low side gauges), would be to fecover the refrigerant and pull
a deep vacuum on the system. Once vacuum reaches ~27 inches, the pump is
turned off and the valves closed and we observe the gauges... If and how
fast the vacuum drops will have a bearing on our repair strategy.

Venting refrigerant of any sort to atmosphere is illegal in my province -
something I agree with and will support to my last breath (think about
it....). Topping off with cans from Partz R Us has the possibility of
causing system damage (especially in the case of a misdiagnosis) or
contributing to pollution.

While I applaud and even help DIYers with auto repairs (and saving money),
some auto repair efforts are inappropriate for those without specialized
knowledge and equipment.