This is me to a "t". Nice description. Many/most people I meet would never guess that I consider myself an introvert and have consistently tested that way on the Myers-Briggs (INFJ). I am capable of being chatty, silly, humorous (I use humor to overcome my social awkwardness at times), and downright outgoing in the right situation. When I used to entertain family a lot (back when my dad was still alive and our family was a lot closer), I was often the center of attention, the most outgoing person in the room. But those "efforts" wore me OUT.
When I was working I much preferred to be social at work and then leave my weeknights free for just DH and me at home. And on weekends, bike club rides were okay during the day, but I hated having actual social plans for weekends and would sometimes make up excuses not to go to parties and get-togethers as I dreaded them so. But if I did actually go to one, more often than not I had a fun time and was glad I went. But I'd need some down time after. And if either set of our parents came to stay with us for a few days, it would take days of "recharge" time for me after they left.
Being an introvert doesn't mean I never feel lonely or feel like I'm missing out on a lot by not being more social -- I do. But it's harder to overcome all the barriers and protections I have built up to avoid social interactions any deeper than a quick chat in passing. And the fact that my DH is even more introverted and less social than I doesn't help matters any!

