The bigger problem that nobody mentioned is that you're buying expensive materials and then letting them go to waste, which is frustrating and costly. But the truth is acrylic paint is really unforgiving - it dries too fast to allow procrastination between sessions. What worked for me was realizing this isn't about willpower, it's about physics: if you leave paint exposed to air, it hardens. So the system has to be failproof.
I started doing three things at once. First: after each session, I store my brushes already wet in a cup of water (yeah, they can sit there for days without any problem). Second: the paint I've opened, I put in a plastic plate or a reusable coffee capsule, covered with plastic wrap - that buys you an easy week. Third, and this is the trick: I divide the canvas into small sections and treat each one as a "completed project." You don't think "I have to paint the whole canvas," you think "today I'm doing the background" or "today I'm doing the face details."
But watch out for this: acrylic paint over dried acrylic paint is way harder to work with than wet-on-wet. If you leave it two, three days, the result ends up with visible layers and rough texture. If you're really going to let time pass, it's better to use mediums that slow down drying, or just accept that you need regular sessions - even if they're small. Half an hour every night, without fail, works better than a whole weekend after a week of doing nothing.