Like others have pointed out, love is an emotional roller coaster.
Being in a relationship can be an emotional roller coaster. Wanting something you don't have can be an emotional roller coaster. Conflicting interests can be a... " ". Love, itself? It usually leaves me feeling at peace.
When I say trust, I mean security, spiritual attatchment or longing, and a deep understanding of the other individual.
Trust is more accurately the willingness to let go. I would call it attachment, although I would use the word connection, the distinction being that a connection doesn't have the connotation of being tied to something. Letting go is exactly that: you let go of your desire to control, attach yourself to, exercise your will over... and you let the other be free. Love requires freedom. You cannot be forced or force yourself to love.
When I say joy, I mean a constant state of positivity in which there is general happiness and comfort despite the fluctuations and changes the emotion undergoes through time. You may have viewed it as a form of elation or excitement instead.
Joy is another aspect of letting go. It has nothing to do with happiness, which is circumstantial. It isn't a state, either. A constant state of anything is boring. Joy can become the essence of something. It is associated with a sense of fulfillment, peace etc. This essence can result in quite a few states and the nature of the states that it will effect are not likely describable as negative, but joy isn't any of these states. It is the essence that brought them into being. This essence can only be found when one has let go.
[...]we are using three two-dimensional words to describe a near infinite amount of opinions, experiences, and abstract ideas of two different people.
Yes, language is arbitrary. Its symbols are arbitrarily associated with concepts, which are carried over from generation to generation with some modifications over time. Sometimes the same symbol elicits a different concept to different people in the same moment. Is this question a linguistic one or does it seek to understand how different people experience a concept that it assumes everyone has, yet which it lacks the means to describe without a simple linguistic symbol?
I will go with the latter. Being in love. Hmm. The expression is used differently as a person ages. At first, it is used to describe infatuation, or a major crush. Later on, a crush can turn into a relationship and the couple may use the term 2 days before they have a violent breakup. Irony. Misuse of language? Arguably. Mostly, I call it naive. The more one seeks to understand love, the more they can try to overcome their naiveness or perhaps they become hurt and believe that it is impossible.
As for the emotions experienced through love, there are too many to name. Love, itself, isn't an emotion. If one ever reaches it, it is likely that they will learn that, to exist, it must become the essence of one's being.
Agapooka