Ok, so the REAL question was whether 90 lb from a frame pump was ENOUGH pressure. The writing on the tire, max pressure, blah, blah, blah were all just red herrings.
Alright. Here we go.
90 lbs is about as much as most of us can get from a typical frame pump, unless it's something like a Roadmorph or Lezyne Micro Floor Drive HP. 90psi will get you home or to the next stop where you can top off your tire with a "real" pump. Since you're a big guy, you do need to be careful if your pressure is low.
The pressure listed on the sidewall is the max pressure. Use the psimet's guide I referenced earlier to determine what pressure you should be using based on the tire width and weight. You may want to use least 25mm tires given your weight.
If the pump you bought is one of the two that I listed, then it's probably a good investment. There are many pumps with gauges that go to 160 but actually getting above 100 with them can be nearly impossible. The Lezyne and the Roadmorph are both proven performers.