I've had unmet social needs for years. One thing to acknowledge is when you move cities/countries, it takes years to build a network. My criteria is: You need to change jobs at least once in the same city (or student->job) before you feel like home, because you need to keep 2 groups of acquaintances. So if you've ever moved: It's not because of you, it's the integration process. I'm making my life choices accordingly: I refuse jobs which require me to travel/move, even though I'm single. Mental health is at this price.
I keep organizing parties at my place 3 times a year, for stupid reasons (Hey guys I'm a CEO now! It's like I'm king of the world, let's make a party for my sacre and all dress like Napoleon) (half-birthdays when you're >32.5 years old are another legit reason for a party). Because I have hard times making friends, the people I invite are very random: Two gay guys I've dated, a gym friend, a judo friend, a workmate, a guy from church, three girlfriends of a former flatmate... It's sometimes awkward but they have in common that they're rational people with an understanding for empathy. Yesterday was my 6th party and this little group got acquainted with each other, so they do enjoy coming. And two of them have dated, which means I upgraded to being a platform ;)
But it's a slow process. I still feel like shit depending on the season. I find it hard to manage my levels of hate (hate against the people who abandonned me, hate against the current system which privileges others, hate against smokers who are responsible for my asthma, etc), and hate is a separate thing which makes you actively wreck social bonds, in addition to depression itself, if you have any. A psy may be important.
Ah and do some sports-camp holidays, many times a year. UCPA in France is awesome for that, until 39 years old.