What kind of mindset should I have to strive for a healthy lifestyle?

Fast forward. What you do now will have an effect the rest of your life.
Focus on… Focus on: 1. Improving your diet. 2. An exercise program. 3. Stress reduction. 4. Avoidance of toxins such as nicotine, drugs, and excessive alcohol. 5. Associate with people with similar/positive outlooks. 6. Ample rest/sleep/recreation time. Seek professional help in any of the above areas as needed. Best wishes.