I'll admit it: I spent most of my teen years and early twenties in a haze of negativity and apathy. While this certainly makes me a pot coming to preach to a kettle on the matter of being positive, I think it also makes me amply qualified to speak about how turmoil, both inner and outer, drags a person down.
When you are facing challenges, and for each person this would be different things, it is sometimes impossible to see past the current woes to any possibility of a better tomorrow. In fact, it always seems much easier to be 'realistic' and accept that life is against you for some mystical reason that is out of your control.
The pit falls of this type of thinking are vast.
First and foremost, it leaves you cynical and depressed which robs your life of any joy and often prompts you to rain on others people as well because misery truly loves company. When you are unable to be positive, your motivation suffers and as a result your productivity in all areas of your life will state to decline.
Further the quality of your relationships will also decline because your constant down state will worry those that care about you the most. Constantly having to prop you up, only to be faced by your dismal outlook may well cost you a few friends.
Changing this habit of embracing turmoil with a shroud of dismalness takes coming to a decision to take another path. Choosing to believe that something good can come your way, even in the lowest part of your life, will require a lot more effort than sticking with a belief in the worse.
It is harder because it is worth it.
If you have spent years brandishing the negativity hammer, disarming yourself will prove to be one of the hardest habits to break. Even without help from you, your mind will continue to generate multiple sad endings to your life and counteracting them will take deliberate intention.
The key is stubborn consistency; it is now necessary for you to cling to the positive in the same manner in which you brandished the negative. Counter all of your thoughts with a more positive alternative and even when you find yourself wallowing a bit in self pity, firmly change that channel to one that bespeaks of a more wholesome outcome.
Know that you may find opposition from anyone who used gladly join you in your daily recounting of woe. As you move away from that bad habit, ground it within yourself and make it personal. Breaking a pervasively bad habit like negativity will take a long time and you will fumble along the way. The key is to not let anyone else get you down with their predictions, continue to work on keeping your thoughts at a high vibration.
Thoughts are only one part of the equation but I think it is the most important. When you disarm your negative thinking you empower yourself to start looking for solutions. As you continue to focus on the solutions and not the issue, you gain momentum which will spur you into taking action to change your circumstances.
I know from experience that much of my negative whining never lead me to changing anything. It only served to keep me in the same position which I was complaining so strongly about.
Having seen the power of being positive put into action in my life, I know that there comes a time when you do need to vent. I believe that this is good, and has its place, but that time should be kept to a minimum. The best use of ones energy is focusing on what good remains or can come from a situation and focusing all attention there.
When in doubt, be positive. And if that doesn't work, keep trying.