Don't talk
Have you ever been excited about some future goals or plans? How did it go after you mentioned them or talked about them with others? I guess not too well. That doesn't mean you shouldn't have goals; it just means you shouldn't talk about your plans or goals.
While it may help with accountability in some cases, it's usually a counterproductive thing to do. While you are explaining how you are going to do everything, your brain is releasing the feel-good emotions of the things you are going to do. Since you already got your cocktail of neurotransmitters, you'll lose the motivation to pursue that goal.
Let's say you have a goal of reducing 15 kg of weight or reading 100 books in a year. Break that goal into actionable steps such as going to the gym regularly for 2 sessions a day and not eating any junk food or added sugars, or reading 1 hour a day before bed regularly. Make it a ritual so it's easier to get into the groove. Also, don't beat yourself up if you miss out on a few days. Pick yourself up and continue doing it.
So next time you want something, plan it out on paper and just execute it. You can celebrate later after achieving the thing.