As always, I don't know how to link this to my previous posts in Newcomers 'need some help now with separation'. I've been thinking about whether I should move and I have found the advice on this Forum pertinent to my situation more than on any of the others. So here I am, if you'll have me.

A brief resume
Me 43 W 42 D4 Together 17 years, friends for 20.
End September got the ILYBINILWY speech etc. W wanted to have fun, party more, wanted 'boyfriends' but not a serious relationship. Wanted her life at home with me and D to be 'central', everything else to be 'additional' to that. 7 weeks later told me she was going to start seeing an ex colleague which she did once a week. Became physical. 2 months of torture with her still at home but staying out all night with him once a week. W became hardened though in her own words 'consumed by guilt' and just said it was all about her needs, finding her happiness etc. Mid Jan I could stand it no longer and asked her to go.

She is still seeing OM and has been living with him for the past 3 weeks while she waits for the keys to a rented flat. I have seen her on a few occasions when she's come to see D, who, thank God, is with me. I have really struggled at times but am healing.I have been working very hard on being a better, happier person. I don't really have any hope of her coming back but would like to stay on here so I have a better understanding of what's happening.

Why do I think it's MLC?
Her age, obviously
Her desire to party, party, party. OM is much more of a party animal than me, is a big drinker like her, nice enough guy but somewhat irresponsible
Her very low self esteem which she acknowledges but has never done anything about
I'm pretty sure she's depressed as she has many of the signs
Her general attitude of 'me, me, me'. This week she has behaved like a teenager, pleasant when she wants something, sulking and trying to renegotiate boundaries when she doesn't get her own way.

However, on the whole she hasn't been really unpleasant, just cold unless she wants something from me.

So am I in the right place?