If people don't ignore you for months, don't care enough to help, don't visit...I wonder if 'friends" is the right word?
The only other thing I thought of is -- do you ASK FOR WHAT YOU NEED?
People get so stuck and preoccupied that they give themselves permission I think unconsciously to let things (and people) slide.
If you are happily (not complainingly) assertive, ex: "Hi X, this is Tupp...sorry I missed you but I'd like you to call me back tonight or tomorrow. Talk to you soon!" If they ignore a reasonable request like that, then you're calling the wrong people.
Likewise, with the oblivious 2-earner: "Hi, I'd like to get together but I wanted to say that I need for you to come over here this time, because of ... (brief reason). I'm wondering if you'd be willing to do that next week?" And if that's a NO or excuses, or no return call, etc. -- another one bites the dust. (Foolish of them, but people waste good people all the time.)
And if that happens, good person, you carry on. You DO have a wonderful capacity for friendship. Go forth and find 'em!
Think of it like dating? I've been on dates with about 20 people this year. First or second dates only. And I'm not mad at them and they're not mad at me because I was real, and I kept it LIGHT until I had the chance to meet them and pay attention to how it felt, etc. I am not going to stop this time. If I keep it up for years, so it goes! I am still meeting and enjoying people. I'm not grabbing on.
Etc. If you ASK FOR WHAT YOU NEED (which is normal and okay) and then RELEASE THE OUTCOME (they get to decide whether they can or want to meet that need or not)...you've done all you can. And the river moves on and it will bring you new people over and over, and now and then, one of them in a bright little boat is going to smile and wave and invite you on board for a cuppa.
I sure would, were I lucky enough to live near you.
Hugs
Hops