Note that there is no past perfect tense (had wanted) or present perfect tense (have wanted) in Russian. All of the forms gsold gave are simple past tense (wanted), and using the perfective verb захотеть instead of the the imperfective хотеть implies "no longer".

As for the difference of я захотел versus мне захотелось, maybe native speakers can tell us whether they perceive any difference between the two. In my explaining dictionary by Dmitriev, the explanations for either are almost exactly the same.