1. GET RID OF ANYTHING UNHEALTHY IN YOUR HOUSE
This is a big one, and the reason I made it number 1. If you habpve anyhing unhealthy in your house it will cause you to get off track. Go through your cabinets and throw away any cookies, candy, ice cream, boxed foods. Anything that is processed or has high sugar content. If you have roommates or a spouse that like to eat those things, ask them to put them somewhere where you can't see them or find them. This will help in your discipline. Then yiu can't buy any of it either.
2. SET REALISTIC GOALS
Often times people find themselves setting high unattainable goals. Determine for yourself, what you think a good goal is, something you can achieve. You can start by setting a really easy one, and increase as you accomplish it. Going along with this, a goal does not always have to be number based like loose 20 pounds. Numbers are daunting and make you hyperfocus on loosing that exact amount of weight. instead try setting goals like being able to run 30 mins without stopping or being able to fit into a specific shirt in your closet. Often times those goals change the way you think about the whole process and make it easier.
3. WRITE YOUR GOALS DOWN
After creating your goals, write them down and out them somewhere visible. Your mirror, fridge, front door. Some place you look often, so that you can be reminded of them. You might make a couple copies of them and put them in different places around your house. Seeing your goals helps you to keep you accountable.
4. CREATE A GOOD WORKOUT SCHEDULE
Often times people think to loose weight or feel better they need to do super hard workouts and kill themselves. That is not true. Find a wide variety of workouts you can do (you don't have to love them, but they shouldn't be miserable), and create a schedule to do them. Actually section out a block of time in your calendar to do them.
5. COME UP WITH A REWARD FOR YOURSELF
As elementary as this sounds, by coming up with a reward for yourself like treating yourself to a new outfit or pair of shoes. This will keep you motivated when it is hard.
6. MAKE ROOM FOR FUN
Make sure you aren't driving yourself insane by doing too much to focus on your goals. Allow yourself a rest day, or to have one cookie. But also be cognisent of when you do that. Don't let yourself have 8 cookies, but one is okay. Perhaps set a "cheat" day where you can have sweets or a chart where you mark what sweets you had that week so you can limit them. Now I did say get the junk iut of your house, and yes I still think you need to do that. If you have a box of cookies lying around or a bag of candy then you are prone to eat more then just one oiece at a time. Self control is hard. But if you go to a part and they have brownies, you can have one, or you can buy one sweet from the bakery and it's okay. Just stay away from large amounts of the bad for you food