“If you’re the smartest person in the room, you’re in the wrong room.”
I know saying this is easier than doing it, but; seek upward movement until you no longer feel like you're the smartest person in the room.
I would also add, although it's purely personal opinion, that seeking a solution to loneliness through work is a surefire way to feel more lonely. You say you're big on self-improvement, but are you only focused on improving your work-related skills? All areas of life need attention, and it sounds like you've only been focusing on the work part of work/life balance (work/life balance is so much more than just what hours you work).
I know saying this is easier than doing it, but; seek upward movement until you no longer feel like you're the smartest person in the room.
I would also add, although it's purely personal opinion, that seeking a solution to loneliness through work is a surefire way to feel more lonely. You say you're big on self-improvement, but are you only focused on improving your work-related skills? All areas of life need attention, and it sounds like you've only been focusing on the work part of work/life balance (work/life balance is so much more than just what hours you work).