We all choose the thing that we believe is going to make us feel better. Emphasis on believe. Most people are looking for that special person that will make them feel awesome. Being in a relationship is better than not being in a relationship. Once in one you should always be happy. Life cleared, mission accomplished, happy end.
As we all now that is far from reality. You can have an accurate perspective about something or an inaccurate one. If there are negative experiences then the perspective is the problem. Let's pick apart the general idea of a relationship between two people.
A relationship implies connection. The idea that you need connection with anyone/anything shows the core problem. The cause of discomfort and suffering is the thought that you are separate from the world around you. If you imagine that you are in a bubble that is not connected to what is around you therefore you must attract everything from the "outside" like a black hole. All of the thoughts, feelings and actions that come from that flawed point of view will cause flawed outcomes/suffering.
The good feelings come when that perspective of being separate diminishes, or disappears, because you feel connected to something outside of yourself. That is where the happiness comes from, not from anything else.
Why is separation an illusion? Without your heart you would die.You and your heart are one. Well if the sun disappeared you would most certainly die. You and the sun are one. Without air you would die. You and the air are one. Without the Earth you would die. You and the Earth are one. Without the world around you you would die. You and the world are one.
You are in a relationship with everything already. Nothing you do can change that fact. That is your true nature, not the false separate idea of you.
Happiness is discovering who you actually are. Oneness.
Happiness is found in oneness, not in parts (women, men, money, etc.)
You perceive that you are a part that has to find another part to be happy, but you can realize that you are all the parts.
Puzzle solved!