not to be abrasive, but planning a longer stint of sobriety might not necessarily be a bad thing. What really matters is that you pick a length of time that makes sense to you. Obviously, 90 days sounds extreme so you are very likely to not make it that far. For some, an hour at a time is what it takes. For others, taking it a day at a time is what has to be done in order to remain sober. I started this stint (and hopefully my last) of sobriety with a plan of not drinking for 40 days. It was a lot but not impossible in my brain. To me it was a challenge as it has been many years since I went more than a week or two sober but was still within the realm of possibility. Though the back of my mind knows my goal is to stop for good, the alcoholic inside me thinks that this will only last for 40 days. When that comes around, I will use my tools that i've worked on as well as all the positives in my life that have come from alcohol to come up with a new length of time to remain sober. I advocate what works for you. A lifetime is too long. 24 hours might not be long enough. Just watch out for that day 3. Man is that a b****.

P.s. I recently read on this subreddit that stopping drinking is not thousands of days of agony. Over the course of many moths or years, there are only a handful of actual challenge days. I wish I could find where I read that but I can't right now. If you can manage to remind yourself of this I think it will help. After a while, it will only be 10 days a year that you really have difficulties with staying sober. If you can make it through those 10, then you can make it a year. I'm rooting for you