That's not a good definition of love. Counterexample: most parents love their children, and yet don't just accept them for who they are (at the moment), but try to change them for the better, by raising them. You can love yourself in the same way.
Growth, as we mean it, is a positive thing. It isn't a value statement that you are inferior as you are and only through growth will you have value and be acceptable.
Accepting (and loving) yourself for who you are is seeing that you have innate value with all else stripped away. It doesn't matter if you never grow, or in fact, if you decline (as we all do, if we live long enough). You see that you still have worth despite this. You have your lifetime of experiences, your hopes, your dreams, that which makes you who you are.
Growth is one of life's biggest joys. Depriving yourself would be a shame. When you have accepted yourself for who you are and then srive for growth you aren't saying, "Once I have achieved X, I'll be more worthy of acceptance and love". You are instead saying, "Let me explore the heights to which I can climb in this human experience". You might epicly fail, but that is alright, because you are fine with who you are. On the other hand, if you are insecure with who you are and don't love yourself, then growth becomes a risky endeavor. Should you fail, it is further proof that you are an inferior person as you weren't able to live up to your ambitions.
You can accept yourself and be content/happy and still want to learn new skills, try new hobbies, and grow.
I think the better word here is contempt.
Bit of a corollary but I've just never been motivated by love. E.g. I don't feel driven to perform well because I love my teammates or love my company or love the world and want to do good by them. It's always a hatred-contempt of wanting to prove someone wrong or to prove that everyone else has been doing it wrong (whether on a team level or a world level). That's actually why I stopped being too chummy with my direct teammates. If you like someone too much, you lose the desire to brutally outshine them. Some part of you pulls you toward the group average so as not to become ostracized.
I don't think that a genuine love for humanity will give you the energy to do good for humanity. It must come from hatred-contempt, there is no other way. "Let me show you fucking animals...". It will never come from "I love you all so much let me build this for you."
You still grow but in the direction and with the motivation you decided.