Not a judgement of your age or fitness level (but rather of mine).
I camped for years on ethafoam, then a 1.5" Thermarest, then a 2" Thermarest. Nearing my 40's, I began to avoid sleeping on the ground.
I now have a 3" and love it.
None of us are getting any younger. If 2" is comfortable, it's not likely that 1.5" will be as comfortable and will be perceived as less and less comfortable over the years--and also remember that pads do break down.
Stick with 2", order custom if you have to. Or check out the DIY pads