Admission to nursing school
is very, very competitive. They turn down applicants who can be successful because they don't have space to accommodate everyone who would make it to graduation. This means that you're among the most capable and among the most likely to succeed. This doesn't mean it will be easy, it simply means you do have the abilities to survive.
Realize there is a 'point of diminishing return' on studying: which means there's a point at which you're putting in many hours just to get a point or two higher grades. Be happy with an A- or B+ (or whatever your personal goal is) and don't deny yourself time with your kids or an occasional movie just to go from a 92 to a 94%.
When you study, devote that time to actually studying. Don't get distracted by checking emails, playing one more computer game. or checking Facebook. Instead, decide how long you'll devote to studying then walk away after that amount of time has passed. Then you can spend 15 minutes on social media.
Think about your journey in semesters or blocks of classes. Get through each day and focus on the end of the semester or class. It's easier to set your sights on finals in May than graduation in two years.
Make sure you reward yourself along the way. Take your kids to the park, soak in a bubble bath, meet friends for lunch... whatever gives you a little break and clears your mind. It's easy to burn out on school (or nursing when you're working).
Best of luck to you!