Our friendship has run it's course

How do you really know when a friendship is truly over? Honestly how many times do you put up with someone's shit before you decide you no longer want too. Let's be honest losing a friend, especially a best friend can be as hard as breaking up with a lover. I'm in my mid twenties now & it took me a very long time to realize in a lot of cases I deserve to be treated better. I'm in the point of my life where I don't have time for negative people or someone who is just an all over terrible person. Like this friendship has really run it's course but you kind of suck as a person. If someone does not bring positive energy into my life & watch me grow there's really no point. I think my main problem with myself is that I'm way to forgiving as a person. Literally someone could do the most fucked up thing to me & I'd still forgive them. Sure it may take time but eventually I will forgive. I've been through a lot of messed up stuff. Things have happened to me that have hurt me beyond repair. The sad thing is most times I say sorry for things that aren't even my fault. I care too much to have a clean slate. Not to say I haven't done messed up things to someone but over the past few years I've grown as a person & learned from my mistakes. I think I need to become a stronger person by telling someone who screwed me over , been mean to me, or just hurt me to just fuck off. I shouldn't have to deal with someone's bullshit. Forgive & forget right?? I used to just go cold turkey with someone & stop talking to them randomly. But now I think even if I'm really pissed off at someone they deserve to know why I'm cutting them out of my life. But back on the topic on whether or not you should cut someone loose. If you are constantly fighting with your friend or everything they do pisses you off, let them go. If they have broke your trust in any way shape or form, let them go. If they try to put you down to better themselves, let them go. If they seem to only be using you, let them go. I've stuck through friendships just because we'd been through a lot together which isn't okay at all. I've repeatedly let a friend treat me like shit before I got fed up & called it quits. Basically if you treat me like shit there's really no point to continue this friendship. I can easily let someone go & so should you. Be with those who love you & want to help you grow as a person. Food for thought.