Nice to see you post again. Sorry I didn't see the post sooner!
Good job on doing the series for 8 months, and for still doing it. Obviously you've gone through the series more than once. I'm sure most of us need to go through it many, many times before seeing the type of progress we would consider fully overcoming social anxiety. But, still, even in the beginning, you feel and see the progress, like some of the things you've described.
I believe it's in Session 4 where Dr. Richards begins to talk about how we move our therapy strategies into the "real world" by always looking for the easiest thing to do. Stepping it up, then, bit by bit. We practice something new in as low level anxiety situation as we can find, to start. Then, we move it up bit by bit. Of course there isn't some clean, perfect way of doing this. Just go about this naturally and with the situations you have to work with.
Your post here reminds me of our group members. They come to the group, they begin to do things they never thought possible. I see them doing such a great job. We go out and do some amazing stuff together. And yet it can still be hard to encourage them to come out to events the next time. When they come, they usually are so glad they came, the "doing" helps to break down the anxiety. Yet, they are still working to change the tendency of avoidance and anxiety. Again it takes time.
The one thing we do have here is the group, so we can practice the therapy together. So, my first thought is, can you find someone there to perhaps begin discussing the therapy with? Perhaps post in some kind of meetup group that you would like to know if there are others, simply others who want to work on social anxiety, or, then, others using the series. I know it's hard to find even that, but I'm trying to think of how you might find at least one other friend/person to work with together. You may find a lot of help in moving the activities up and out together, and just talking about it.
My next thought is about what you write. I'm sure you know already - you are feeling better and it is when you are not worried about anxiety that it isn't a problem. If only we could stay in this mood all the time! But then thoughts have a way of creating our feelings. Other times you feel anxious. You feel like you don't even know why or what is making you anxious on those days. I would argue that you are still having some thoughts on those days, thoughts that you let go unchecked, ANTs that are still being allowed to create a mood without being stopped. Apply the same fundamentals to all the ANTs and ANFs.
When you're in the situation with your parents, even, on "bad" days, use the statements from the therapy. Don't settle for these feelings and the moods or you will get the result of irrational thoughts. Even though you are feeling anxiety, IF YOU MAKE THE EFFORT TO APPLY THE THERAPY, then you are making a difference, long term. It is exactly when you feel anxious that if you do choose to still apply the therapy, say it to yourself, that you are at that moment signalling to your brain that you will not allow that way of thinking to go on. You're making the rational, calm neural pathway more possible for the next time.
I feel like I don't know enough about your life and your situation to give suggestions about what exactly you could be doing. I do feel like you may know how you can continue to move the therapy into your real world situations, or to find and create situations to practice the therapy behaviorally. I feel like you have a solid understanding of the cognitive therapy but that you may need to DO things in a structured way to help that feedback cycle of thoughts to feelings back to thoughts again.
You just cannot allow the anxiety to get expanded and go into spiralling ANTs. When you are talking about or thinking about these situations with your friend or upcoming events, you do need to just stop it. Stop the worry part, emphasize the rational part, and always stop it. By allowing the thinking about it, you feed the anticipatory anxiety side of things.
How can we get you a partner to do therapy with? How can we get you a coach, a teammate? No matter the country or the culture, about 7% of the population will suffer from social anxiety disorder. So, you are not alone there.