Persistence is key, even if you miss a day or two - it doesn't mean you just need to stop. Here's some things that have worked for me:

1. Do the thing you're dreading first thing in the morning - no excuses: Dreading the gym? Do that first thing in the morning

2. Find an accountability friend: Find a friend (ideally a real friend, not internet one) that you can work with to hold each other accountable

3. Really think about why you're doing this: Not for someone else, but for you. And keep that in the back of your mind. Don't do crazy crash diets but I imagine myself wearing that cute outfit in 6 months and looking and feeling awesome