Hi princesseli! Yes it is too exhausting because it doesn't come naturally. Not only that , when I am included in a new "group" ( not good in groups) people are nice and inclusive until they realise that I'm different and not naturally social. That causes feelings of inadequacy and rejection which I can do without.
I feel the situation is different for you as you are at a different stage of life. When I was 20 I had some Chinese friends, then a Chinese boyfriend.....as our cultures were so vastly different my "weirdness" went unnoticed, in fact I sort of fitted in as to show disapproval was culturally a no no for them. When I didn't have these friends I was a loner not knowing how to meet , initiate and maintain a friendship. I'm now considerably older, had one divorce , travelled aimlessly overseas, and finally married again. I am childless. It might be significant that both marriages were to men born in Europe from cultural backgrounds very different to my own.
My friendships have formed with people involved in the same activity.... I've not joined groups to "meet" people I've joined activity groups because of my passion for the activity/interest....and from that I've met people who share a common interest. Some of these people remain "friends" but often most drop by the wayside. I think this is the same for most people not just Aspies.
Once the activity group ceases to exist these " friends" may disappear of become sort of like acquaintances. Very rarely will a long lasting friendship, as NTs have, continue.
What are your passions! interests! Follow them up via some sort of group.... for example I've joined various groups over the years.....dancing.... writing....philosophy discussion, painting.
NEVER joined with the purpose of meeting people but to enjoy sharing my interest with others.
Hope my ramblings have been of some help !