Hoping - Mesilas yeshorim starts with "yesod hachassidus veshoresh ha-avodah hatemimah" and he explains what the foundation and root are. yet later (or before, I don't remember) he writes that the true chassidus is "rochok mitziur sichleinu" meaning we can't even imagine what it'd look like, if we tried. Not a contradiction? It seems that having a good goal is necessary, even though you don't really know what it'd be like to live like that!
Actually, he may be telling us that if our big goals in life are things we see and can relate to, we are cheating ourselves. Besides, what happens inside when you reach the 90 day goal? (remember the agadeta about the chazzan wgo stopped and the chochom asked him, "So, are you done praising hashem?") How many days are enough? What happens then? Rather than having a goal of 90 days, 100 days or whatever, why not make your goal having proper awareness of Hashem all the time (yirah), or living for giving (ahava), or something like that. Sounds good to me. Then set about getting there by being sober each day and growing in the steps. Can't get there if I'm not sober... If this doesn't help, sorry. if it does, your welcome!!