Believe in possibilities. It has been said that misery loves company and also that like attracts like and birds of a feather...you get my point. Words and actions are important, but they are not the attractive force--like feelings attract like feelings. Thus do actions and use words that produce good feelings.
The Law of Inertia
An object in motion tends to stay in motion and an object at rest tends to stay at rest, unless the object is acted upon by an outside force.
Positivism is infectious, it grows and spreads in its own presence and will continue to do so unless acted upon by an external force. The same is true of negativism. Negative thoughts breed negative feelings, beliefs, actions etc. What can you do as protection against external forces?
Participate in life without being a sponge for the world's problems. Helping others is not the same as solving or fixing the problems that are not your own. Learn to be a facilitator--one who helps create conditions which guide others toward blissful choices. Empower others to solve their own problems, accepting when they choose to continue living with their problems.
Detachment in partnership with conscious awareness and intentions stabilizes your chosen outlook and thus enables you to control your life experiences and perceptions without external factors, such as the emotions of others, dislodging your joy.
The study and theory of Depressive Realism has provided evidence showing that those who are depressed may have a more realistic and unbiased view of their abilities and can more accurately predict outcomes than those who are not depressed. In studies, their judgments have been shown to have greater accuracy than non-depressed individuals in situations that are outside of personal control, but studies also have shown that depressed individuals feel they have no control in situations where they do and in such circumstances their judgments are less accurate.
Whatever your attitude, it is likely to be self-fulfilling. An optimist and pessimist experiencing the same hurricane perceive the experience differently. Though it is not a guarantee, success is a result of failure. Those who succeed, often do not do so on the first attempt, nor the 2nd, 3rd 4th... For certain things, it takes a single success amidst multiple failures--a failure to win a jackpot lottery 100 times and a success once is generally acceptable. Practice yields improvement. But as a person improves so may the competition.
A depressed person may experience failure more often by failing to persevere; the true failure is in the refusal to try again. A depressed person may predict a personal failure and be accurate, whereas someone who is not depressed may predict success and fall short, but that person stands back up again and again, whereas the depressed person likely tried once and gave up. She may not experience success, along with a 90% failure rate. The idea of having a successful outcome is not for each attempt, but for some of the attempts. Fail and risk enthusiastically and rise again and again and again...
A positive mental attitude is self-serving; it is about how you feel, influencing others is a bonus, not the purpose. It will not fix your husband and solve your marital problems. Your attitude can encourage positivism in others, but there is no guarantee it will. If your spouse never comes home, it is not because you didn't smile enough. If he divorces you, it is not because you failed to forgive or you are not a joyful person. If a positive mental attitude were a cure for divorce, the divorce rate would be lower. Joyful people get divorced. They also allow their emotions; though joyful, they are not perpetually happy, they feel sad, hurt, angry, depressed... Those who value themselves and consciously choose joy, do so by validating all feelings.
A positive mental attitude accepts situational happiness. Sometimes a situation or environment may not be pleasant, but even amidst such conditions, you can choose joy. Do not allow a situation to create your personal happiness or mental attitude. It's okay to be unhappy with a situation. Learn to create and choose joy within yourself, where it should have been all the time.