No one prepares you for how to accept that someone you love will no longer be a part of your life. For whatever reasons, your relationship has already ended.
Maybe it never became a relationship, or you can't stand that kind of relationship anymore. Maybe you both wanted each other, but circumstances got in the way. They may have outgrown each other. Maybe he or you have changed or life has changed.
When you have to let go of someone you believed would be a constant in your life, yours change the world. The present, the future, everything you thought was there, that your future would be, it's gone.
Everything reminds you of this person. Everything they are and everything they won't do together anymore. Your feelings are confused. Accept them. Cry when you feel like crying. Scream at the sky, let the pain and disappointment out of you.
Don't fight the pain and anxiety, don't resist. Sometimes you'll feel like you can't breathe. Just breathe, slowly, deeply.
You will feel that you are missing something. Empty.
The pain you are experiencing is normal. You're changing and growing, even if it's happening in ways you can't yet understand.
You will think if you could have done something differently, if it could have been different, why it had to end like this, you will blame yourself, this person, you will be angry both at yourself and at them... It will hurt, but it will pass. You will survive and it will be different.
As much as you want to believe that this was your soulmate, there is a reason why they aren't together, and it's probably not just one, and that collection of all sorts of reasons would eventually end your relationship one way or another.
Whatever story you're creating in your mind, you have to understand that things didn't work out because it's not in that story there weren't two people who were willing to put in the effort to make the relationship work.It's that simple.
Everyone has their own dreams to follow and their own walls to build and tear down.
The other person may not be a part of your life anymore, but you have unforgettable moments and memories to last a lifetime. Eventually you'll realize that it is you have gained much more than you have lost.