You know when all you want to do is make that one person you love with your whole heart happy?
And make them feel like they aren’t alone?
And make sure they know that even when times are hard they will always have you and you aren’t going anywhere?
And when you find out that they feel one little negative emotion about themselves(loneliness, self doubt) your world breaks down because all you want is to make them feel how they make you feel but they are feeling negative emotions.
When that one special person can make or break your day.
When everything they say affects you so deeply and logically it shouldn’t affect you so deeply but it does. 
When you can be so happy one second and suicidal the next just because you feel like you are disappointing them or because you got into an argument and you feel like they might not love you anymore or they want to leave you.
That moment when you don’t talk to them for awhile and you get this really empty feeling in your stomach and you feel sick and like you want to cry.
The moment where you guys get into an argument and you think they really are done with you and you just think of ways to try to get them to stay or become suicidal.
When your whole self worth is based on how they feel about you and what they say to you.
When they make you feel like the happiest person alive and you feel like nothing could ever change how you view them.
And if you think about them not being in your life for even a second you instantly want to die because in your mind or in your heart you know that you couldn’t make it without them and that you couldn’t be happy without them.
When you love them so much you will do anything and I mean anything to get them to be yours forever 
You will change your views on things.
You will try to get interested into other hobbies just to have a sense of identity. it makes you feel like they won’t ever get bored with you if you.
You will most likely take any type of treatment just because you love them.
Sometimes you might completely lash out on them and you just have negative and intrusive thoughts about them but they were the person you thought so highly of but it doesn’t last long because soon you are back to thinking they are the most amazing person in the world.
Not like you didn’t doubt that for a second because it’s always in the back of your head but you have moments where you are really rude to them because they did something that pissed you off and it can last for days but even though you are mad for a very illogical reason in the back of your mind they are still the greatest person to exist.
(Sorry this was a rant and I don’t have good grammar/punctuation at all)