That’s definitely a threat:. “And I will have that active sex life with either her or someone else, but I will not cheat on her (meaning I will leave her if things don’t get better)”. If she already isn’t into sex and suffers from anxiety, after hearing or suspecting that you might leave if she doesn’t have sex as often as you want, she likely won’t be able to do it at all. Sense of urgency (why such urgency?) on man’s part doesn’t make a woman more willing. It actually is the other way around. You want her to enjoy it. Fear that her husband might leave her, absolutely will stop her from enjoying it

I find interesting that you don’t know if she has lower sex drive (which is common as she is 60), I find it interesting that you didn’t even have that discussion with her?

Ultimately you have to decide. If frequent sex is a priority for you over marriage to this woman, I suggest you leave and look for other women (might have to look for much younger, many women in their 60s won’t have sex as frequently as you need). If she is more important than frequent sex, then you start looking into perhaps reasons why she doesn’t need it as often or perhaps look for alternatives.