Relationship advice.

Long post.
I’m married for 3 years and have a newborn.
Been with my wife for a long time and only ever dated her we’re both early 30s
We have a mostly happy marriage even though I feel I’m very appreciated but not loved.
Basically sexless, 1/2months ish. My advances are always repelled no matter what angle I use. Romantic, sexual, favours. I’m basically expected to cook and clean while she cares for the baby which is fine but I have more personal needs that she ignores. Flatly, I’ve gotten on antidepressants not because I need them currently but due to them annihilating my sex drive. When I told her that was my plan she said ‘ok, I’m going for a walk can you grab me a jacket, it’s cold out’.
There’s this girl I’ve been interested in for over a decade. There’s on and off texting history there nothing romantic or sexual just venting about life and such. Shes in a long term relationship w a 4year old to a guy that cheats on her every weekend almost but she won’t leave.
The girl has asked me to visit her and has been really flirty lately as well as talking majorly bad about her partner.
My assumption is she wants me which makes me feel sick.

So my advice I’m looking for.
Do I tell my wife about this? Do I meet her?
Possibly relevant. Virgin outside my wife 🤷🏻