The following answers are provided by Longman Dictionary.
For some of the words, that’s not how I understand them.
Anyway, there you go.

What is Love?
A strong feeling of liking someone a lot combined with sexual attraction.

What is Liking?
When you like someone or something.

What is Obsession?
An extreme unhealthy interest in something or worry about something, which stops you from thinking about anything else.

What is Affection?
A feeling of liking or love and caring.

What is Infatuation?
A strong feeling of love for someone or interest in something, especially a feeling that is unreasonable and does not continue for a long time.

What is Attraction?
A feeling of liking someone, especially in a sexual way.

What is Crush?
A strong feeling of romantic love for someone, especially one that a young person has for someone older who they do not know well.

What is Desire?
Strong wish to have sex with someone.