Has your submission increased or decreased over time?
Increased by a wide margin. I'm willing/able/wanting to go much deeper into D/s than I was at the start.
Have you ever had to renegotiate your submission due to a change in your feelings or circumstance?
Yes. Things had to change slightly with F because our contact got very irregular which hurt my feelings badly and she was rarely available to give me any form of emotional aftercare so I would crash by myself. With T we had to dial things back in the dynamics department due to trust issues that came up. She locked me in isolation and forgot about me a few times. She also had trouble keeping her emotions under control at times which led to abusive situations. 24-7 just wasn't safe for me anymore.