I know exactly how you feel. Both the indecision, confusion even, over simple choices and the sense of sinking in quicksand - or better yet, as you say it, grasping for sand. I feel that often, both in terms of smaller moments and bigger-picture life direction stuff. And I also hate attention, so I hate birthdays.
I wish I had good advice, or could tell you that it will get better, but at least know that I know how you feel. I know it’s not worth much, but you’re not alone.
The Hindus were right all along, this is the Kali Yuga.