Is it wrong to think I'll never be good enough for myself much less anybody else?
Why do you think that you'll never be good enough?
I feel like I am either too ambitious, or not ambitious enough
Everyone questions their self-worth at times, but other people will still think that you are worthwhile.  You shouldn't devalue yourself, just set a good goal and work toward it.  You'll either succeed, or you will learn how to do better next time, and people will notice.
I just feel like I'm the kind that no one will want to be with
You are a person of worth and you should never think otherwise. You should find your goals and ambitions and pursue them with everything you've got. Don't give up and prove to yourself what you can do.