Why do I feel this

[Unknownterritory]

Separated from wife but still living together , we haven’t had sex for over two years and never really had the desire too kids and life took over and we both changed and grew apart , all of a sudden the sexual attraction has come back ??

What do you want us to say?

It's a natural reaction after separation (my therapist explained that to me). It's a biological mechanism, hard-wored into our brain. It doesn't have anything to do with whether you should be together or not.
I would suggest moving out ASAP.