Negative energy can come from disappointment  and anger from your day time job, instead of loosing hope and resort to escaping your problems and engage in other non productive activities, convert this anger to positive energy to help you make your independence more quick.

CENTER OF CONCERN:
Very important, move this center to your core new startup business. Yes, most probably it is tied up to your job socials; colleagues, promotions, work atmosphere...etc. This does never mean that you start not to care about your daytime job, but rather only concentrate on what you have to do there serving your employer's business. Use the rest of your mind space and emotional energy to serve your startup business.

RECHARGE:
Every now and then, recharge, this can be daily or weekly. Not only vacations or relaxing time, but any other activity that makes you more optimistic and boosts your energy and give you power and persistence to go and do something new in your project. This can be playing some sports, jogging, it can also be some book you like or daily article by someone you like reading to, or even watching some show or episode in TV. Whatever puts you in a better mood to work, DO IT.