Over the years I have discovered that, as long as you consistently do SOMETHING to increase your awareness or self-knowledge, you will find yourself happier each year than you were the previous year. It doesn't matter which modality you follow, as long as you don't narrow yourself with rigid belief systems, you will continue to feel more awakened and alive.
Some of what I have to say now may not be too comfortable to hear:
The biggest barrier to personal wellbeing is victimhood: as long as one perceives that others are the cause of bad conditions on our life, the others have the power and nothing will change. Even if there is truth in that perception, blaming others leads only to a dead end. It may be time to just "bite the bullet" and make the best of our situation. Forgiveness can do wonders for peace of mind.
Another barrier is drugs: recreational drugs, but especially prescribed drugs, only suppress symptoms and make it very difficult to address basic causes. Depression may be just the result of poor nutrition, junk food, sugar or mineral deficiencies. My personal feeling is that one should do whatever it takes to replace poisonous pharmaceuticals with safe, nutritional alternatives - and there are many. If your doctor won't co-operate, FIND ANOTHER DOCTOR! "Chemical imbalances in the brain" is just another lie, not based on real science, to enrich the pharmaceutical industry - they are not your friends!
Marijuana can give a temporary euphoria. While it may be a wonderful medicine for some ailments, the high it gives is tiny compared to the natural high of self realization. It is not worth the risk of attack by "blue meanies" if used in a place where it is illegal. If you see the Beatles movie "Yellow Submarine", you will understand "blue meanies".
Another trap is looking for happiness in a mate, a better job, more money or another location. Those things will make you feel better for a while, but until you find the source of joy within yourself, it cannot be permanent. That's how relationships become co-dependent, jobs and places become boring, and even more money does not ultimately satisfy.
Now, on the positive side, there are more systems, modalities, workshops and teachers than ever before to assist you on the road to self discovery. The most powerful and effective one I have found, by far, is the Avatar course.
Happiness can also be called LOVE. When one's attention is fully in the present moment, with no thoughts about past or future, there is only appreciation for the things that are seen, heard, touched or smelled. This is when fear is absent and what remains is just peace. In that peace is your true nature.
The best news is that joy and happiness is your natural state. Any other emotion is caused by activities of the mind. Those are mostly related to events of the past or fear for the future. If there is something disturbing going on in the present moment, it is only your judgment or belief about it that can disturb your tranquility. In such a case, decide if you can take action to help. If so, do it. If not, it may take practice, but just let it be; then your natural joy can reassert itself.
Someone once told me that he did not have the right to be happy while there is so much misery in the world. His compassion was commendable, BUT: how does being miserable oneself help anyone else? The truth is that your happiness DOES elevate people around you - certainly much more than sharing their misery. You can listen and understand someone else's problems without making them yours. Even though smiling or laughing may sometimes be insensitive or inappropriate, the happier you are, the more effectively you can help.
The main point is: happiness is a choice. You can choose how you feel, and it need not have anything to do with your circumstances. Ultimately, only your beliefs can block your happiness; and there are many techniques available to change those.