Decide what you want to achieve academically, professionally and personally and write down the steps you need to realize your goals. Aim high but be realistic and don't over-schedule. You'll enjoy a tremendous sense of accomplishment and self-worth as you progress toward your goal.
This may sound obvious but sometimes we isolate ourselves when things get tough. It's important to reach out when things get rough so try starting a support group or finding an accountability partner who will help keep you accountable and motivated! You can as well join self-improvement community.
This seems obvious but sometimes we beat ourselves up over things that aren't even worth beating ourselves up over! Try keeping a journal where you write down any negative thoughts or feelings that come up during the day so that when they happen again next you have an idea of what's happening.