Why is it that, there is always that one person, thing or experience one just doesn't want to let go? Are you that scared for reality? My answer would be yes. Truth is that experience you are holding onto, the person you're cherishing or the thing you're treasuring all give comfort. Those have began to play a significant role in your life and you're like "what the heck? Nothing will never be as amazing"
That is wrong though. Why? I've realized that by holding into such memories we deprive ourselves from the reality. Instead of enjoyment, we go through grief. All that adds making reality seem like "it's the worst" when quite frankly it's you who makes it that way.
Currently as I write, I experience this. I'm not letting go of the past. I want to cherish it all and when I think about that person, I think "no they don't care, you're nothing". Is that right? Hell no.
Just because of some stupid person I'm putting myself down and not care about present. If I aware of this why am I still here thinking that way? I guess feelings does that. However, develop a strong personality and don't be vulnerable.
At the moment it may seem like it's the end of the world because you aren't with that person but better things always await. Time heals much things but love seems to struggle a bit.
I really don't know if that person cares anymore but I know one thing, "if he holds you back then he's definitely not worth it". Whether care or not, it's time to Let.It.Go.