that's life man. it's never a straight horizontal line, always ups and downs, peaks and troughs, it's a rollercoaster. as time goes on it gets smoother, the peaks don't get so high, the troughs not so low, that's a good thing but actually kinda depressing, you start to miss those extreme, those emotions. all you can do is know when you're on the up and enjoy it as much as you can.
some people never realize they are on the up and they are always miserable, complainers, you know? i'm sure i've been there before .... anyway when you're in a slump there are things you can do to minimize the negativity.
1 avoid situations where you know you'll end up doing something you won't like. this is most difficult for me e.g. i don't like smoking cigarettes, but if i'm around cigarettes find it difficult to not smoke. so, a) i don't buy smokes or have them at home. easy enough. b) avoid going to bars. not so easy, because then i have to not hangout with my friends a lot of the time.
i fallen victim to this twice in the last ten days and both times i wasted an entire day, next day, hungover because i was up all night drinking and smoking, one time i missed my BJJ class, too, and that's something i'm really motivated about, something i wanna do. so .. peer pressure is a bitch, and yeah, it's ok to do stuff like that if you're having a good time, but sometimes it's not even that much fun, you're just doing it because it's easier than saying no.
2 future projection - this is simple enough. you ask yourself "am i gonna feel better or worse if i do this thing?" e.g i should work-out but i'm kinda happy here eating potato chips and watching porn on the internet. might just do that all day ....... which of those activities is your future-self gonna be more pleased with, the one that takes effort or the one that provides a small jolt of stimulation and then leaves you feeling miserable? it's no contest. simple, but not always easy. i mean, i've literally never regretted working-out. i've always been glad i did that. plenty of times i regretted doing other easier, more effortless activities, though.
3 always look for the positive in any situation. this takes practice if you're not already good at it. i wasn't. i was the perpetual complainer, but it can be done. nobody likes a whiner, anyway. so always try to put a positive spin on events.
or, give thanks (try a gratitude journal) at the start of the day, or the end, think of all the things you're grateful for about that day.
don't dwell on things, though. you did it, move on. i wasted a day. not gonna waste the next one, try not to repeat your mistakes. you know what to do.