It sucks at first. You'll hold on longer than you need to, and part of you will be aware of that. Regardless, you'll hold on. You won't be ready for it, and it will be hard at first. But it's a part of life you can learn to accept. I feel like so many people act like it's super easy to let go, whether it's a friendship, a relationship or whatever. But truthfully, it's not easy in the beginning, and it takes a while to feel OK with letting go. At least that's how it went for me (on multiple occasions). But it's something that becomes easier to accept with time.
I used to believe that me and my best friends would remain best friends forever. Now I see that that's a really long time for a lot of things to change that. That's a really hard thing to accomplish. I am most definitely not the same person that I was in high school. I grew, and sometimes the people you are closest to grow, too—just in a different direction.
You'll be sad when you finally decide to let go. You'll second guess yourself, and you'll question whether or not it's really what you should do. But at some point, the need to let go will become so clear that you'll just do it. The negative feelings that come with it are normal, and they'll stick around for awhile. But eventually, you will find peace with letting go.
There's no sense in clinging to people that don't put in a mutual effort. There's no use in hanging on to people that treat you poorly. There's no need to hang on to people that are going down a path you just don't want to be a part of, whatever that may mean to you. If they don't add something positive and productive to your life, there is no real reason to hang on.
You'll learn to be thankful for the good memories and the life lessons that they taught you. You will learn to let go of hard feelings and let what was, be. You'll move on with your life and yourself. You'll make new friends who have grown like yougrown into a person you would like to be around.
Don't force it. I spent too much time trying to make certain relationships work when it didn't feel right, and trying to make people stay when they clearly didn't want too. Don't put it all on yourself. You don't need anyone that doesn't want to be there for you. It's not you. If you are trying your best, it's not you. Save your time and energy on the ones that want to be there, and the people that bring joy and positivity into your life. Good vibes only.