The ability to assess and feel as if one is "fine" with one's situation is highly individualized. If one has had a significant and meaningful relationship, and now it is gone, and is missed, then one might not be "fine" with the situation. Some people do not and may not be capable of bonding with people in terms of their oxytocin and vasopressin hormone levels, they do not seek out relationships, and even the ability to experience love might not be there. In this context, one does not "miss" what one never had, nor ever will have, because there is no frame of reference there.
One can waste a lot of time ruminating about such things, become envious and jealous, which is never good, nor is the depression, anger, and frustration of wishing for something that will never be. "I wish I never had autism." I get it, I understand, but you don't have that choice. It is what it is, now deal with it. You are not, nor will ever be, those "other people". Accept it, move on, and play the game with cards dealt to you.
I am 58. I've been through the process of life, had my ups and downs, and have been pretty darn lucky in life with a wife and children, success in my work life, personal life, and my financial situation. I've never operated on an emotional level. I also have alexithymia. I operate on a logical plane. So, I accept my life as it is, with all its pros and cons. So, "YES", I am doing just fine.