Jess
he has then sent me a text saying he's worried that I'm 'isolated'
Wow, he's a manipulative bastard, isn't he? 
He didn't give a shit when OW was on the scene, did he? Now, suddenly he's worried about you. What a condescending arsehole! Did he think you weren't going to manage without him?!
I remember you saying he picks people when they are vulnerable. Looks like he's trying to make you feel weak, so he can swoop in and play the big hero or something. Well, you've managed this far without him.
I know it's a bit of a cliche now, but the words to "I Will Survive" are so apt here!
Go on now, go, walk out the door
Just turn around now
'Cause you're not welcome anymore
Weren't you the one who tried to hurt me with goodbye
Do you think I'd crumble
Did you think I'd lay down and die?