Defining my submission, again

I do an entry like this every so often because, like any other relationship, a D/s dynamic is always evolving and always changing as the members of the relationship grow and learn, so, occasionally, one needs to reexamine their situation and rethink their role.
Master has a saying He tries to live up to, "People first, submissives second." Being with Master and being under His collar, I have come to think that any Dominant wirth their whip should think like this, no matter the dynamic.
So, what does my submission mean to me, at this point? I have been having trouble figuring that out for myself lately. I guess I am just in a funk, I don't know. The little things that tend to anger Master, and annoy me, are back and much stronger then they usually are.
Being submissive to Master makes me happy, there is no doubt about that. But, at times, I question if I am really the kind of submissive He needs and deserves. He is such a kind and gentle Sominant, and a compassionate one, too. But am I really serving Him in the best way possible?
He deserves so much more. As a slave in the bedroom, I used to think I was second to none, and I can be again, if I just get over some of my issues. But, after over nine years, how much longer can I expect Master to wait for me to get over these issues? How long can I honestly expect Him to wait for me to get my sex drive under control so I am not a horn dog 24/7? How can I get that impulse to argue until I get my way under control before it causes more problems between Master and I or problems arise between my sister and I?
How does one better herself when she does not know where to begin? How do I get this all under control before the faults cost me Master? How do I get them under control before they cost me the new relationship with my sister?
How do I define my submission in my mind when I am at a point where I am unsure of what I am doing? How did I get to this point? I used to be confident and sure of myself and my submission, but, now, I am anything but. How do I get that confidence back?