Imagine a situation, when you are trying do something, give up and then trying again, and repeat this many times. You do this just because you can't imagine your life without something and desperate to get it, but nothing seems to work. You stubborn in your goals, but flexible in the ways. You want to be perseverant, but you don't have enough energy to be perseverant for a long period of time.
What is the best positive word to describe it? I tried Perseverance, Persistence, Sedulity, Stubbornness, Willfulness, but none fits good enough. Or may be I misunderstand them and they do? Desperation fits well, I guess, but I would like to emphasise a positive side of the situation/person.