polarize your 3betting range by threebrtting the top of your range and the bottom of your range. the bottom of your range will be 3bet bluffs and will still have a lot of equity postflop but they will be unpredicyable as well so that when you do hit a strong hand with them you will get paid. I threebet this range with 50bb or more: 99+ / A9s+ / A2s-A5s / A9o+ / K10s / KJo+ / Q10s / QJo / J10s
I flat call this range with 50bb or more: 22 - 88 / KJs+ / QJ / 98s / 87s
this is a more loose aggressive 3bet range. if youre not comfortable playing a loose aggressive style then do not play these ranges because they will get you in dificult spots.
but in this range, 99, 1010, A2s - A5s, A9o, A10o K10s, Q10s, KJo, QJo, and J10s are my 3bet bluffs. the rest are 3bet for value.
it sounds like your playing pretty nitty though so i would recommend trying to transition from nit to TAG before 3betting that wide. dont worry about 3bet bluffing yet, but you absolutely need to add more 3bet value hands to your range. I think a good tag 3bet range should be: JJ+ / A9s+ / AJo+ / KJs+ / KQo / QJs