Your thoughts control you.
Letting go of negative thoughts is important. You are going to think in your own way, but you have to be sure to have some stability in what you think. Losing your stability is why we need someone to be our rock. While there is nothing wrong with relying on someone to hold you up, you will be happier in the long run if you are able to be your own support system. Find a balance that works for you. Redirecting your thoughts to be more positive will strengthen you and enlighten your life. Overall, you're going to feel better once you let go of any negative thoughts and allow the positive, good ones to roll in. Your faith, trust and confidence in yourself will be lifted. You will feel better.
Check out what Harvard has to say about sleep and mood. Sleep has a huge impact on your day, and how it plays out. It will help you to be optimistic by being well rested.
Stop waiting...
"If you don't like how things are, change it! You're not a tree." -Jim Rohn
Think to yourself, "Is anything or anyone FORCING me to stay where I am at and unhappy?" More than likely, the answer is NO. The first step in any journey is to simply start. You won't get anywhere at all just waiting for a change to happen. Sometimes you have to take it into your own hands. It is your life. Take control.
Give yourself some relaxation time!
If you deserve it, you deserve it. Make time for yourself to relax when you've hit your limit, and you have just about had enough. Recharge your mental state. Do what YOU want.
Forgive yourself. Give others forgiveness.
Holding onto things is at the core of negativity. Sitting and dwelling on things that are out of your control will ruin your mindset. If you're upset, take a break and let your negative emotion dissipate and respond with a positive purpose, instead of react instinctively. You will be happier knowing you didn't act without thinking.