You run a mile from the self-important, arrogant twat.
He didn't give this any reflection, his 'sorry' is meaningless because it lacks depth or personal accountability, he gives you a load of pathetic excuses which also serve to big himself up about how important & popular he reckons he is, & he's trying to make you feel sorry for him into the bargain.
Run his phraseology through an Arrogant Twat Translator & this is what you get:
His life is v random right now.
I refuse to be held accountable for my own decisions, & this is my sly way of informing you that I expect you to accept that.
He tries to stay out of his flat
Poor me, alone & needing a woman to love me, & consider me all wounded & interesting.
and accepts invites at short notice to things
But I am glamorous & important & in demand! COMPETE FOR ME! DANCE FOR MY ATTENTION!
especially if they are things that might help him avoid drinking.
I manfully struggle & have mastered my alcohol consumption! Or ... have I? Not sure. Bit pissed. Anyway my boozing isn't the point, the point IS, I want you to minister to me & my needs, or I might not be able to avoid drinking. Please listen carefully, as I need to also be able to carry on drinking exactly as much as I want, but for it to be somehow your fault. OK?
Really hopes he would see me before we went off to our separate Christmases
(Not sure on this one. Could be genuine, could be wanting to keep breadcrumbing you to keep you on the hook.)
Sorry if he did not seem to take our friendship seriously.
WEASEL WORDS ARE FUN. They have all the benefit of appearing to be sincere, & none of the inconvenience of actually doing anything differently from before. "Sorry if" & "seem" are my 2 best weasels, I saved them especially for YOU. That's how much I care.
Inviting me to a swanky party
Swoon at my VIP lifestyle. I will Love Bomb you til you squeak, baby.