@AlwaysAllegra
why are you making the effort still with these people?
It sounds like you feel guilty you’ve done well in life (very common young female over-achiever tendency) and that you owe others something. You really don’t.
There’s nothing wrong with you - you’ve been busy with work and achieved lots and if you’re a high achiever it’s going to be harder to find people “at your level” to connect with.
You don’t need to grovel or “try harder” or be a doormat just to be a “likeable woman” . Ffs.
Seriously I can’t imagine someone telling a man to weep at his desk and “show vulnerability” and change his personality and do Lorraine Kelly style confessions on his personal problems in order to be popular? 
Being in a dynamic where you’re giving and getting nothing back is going to screw with your self esteem. Yes, jealousy and class and money envy do exist.
Just think of all the people you’ve done one sided things for, and drift away/ghost/take a break for a while.
Then slowly go out and meet new people but maybe at the same professional level as you? (Alumni or networking organisations - avoid free/cheap events)
If you search mumsnet for “I have trouble making friends” you will find a lot of women in similar social positions to you
Plus I think go in with low expectations - you can’t easily recreate close university social dynamics once everyone is doing their own thing (I’d be very suspicious of any older person who wanted to do that tbh or who wanted to be “one of the girls”
- I’d think they were needy or strange).
You might have to adjust your picture of how your friendship group is “meant” to look.
So rather than having one person you are on the phone with all the time, you might go on a pricey group holiday once a year with other middle class thirty somethings (they’re not just for weirdos if you google you get really cool solo traveller holidays) and have someone separate to go to the theatre with.
Or maybe a friend or two in different cities where you visit each other for weekends once a year.
If you’ve never had a BF or a group of female friends that doesn’t make you a freak it makes you quite a normal middle-class person.
By definition if you’ve got a full on job and a partner and are career focussed you’re not going to have the emotional energy to run a dramatic Sex and the City style social life where you live in each others pockets on the side (and neither will your peers)