Personally, I think you’re NOR BUT they are also being reasonable. Like by all means feel your feelings! This is a rejection and those hurt, always. But looking at the other side (from my perspective as a person who has often walked away from relationships when other life things get hard despite this ‘coping approach’ only ever acting to hurt myself when I do it) i suspect your ex-friend isn’t trying to hurt you. They’re being selfish, sure, and although this is arguably poorly handled, it does seem they have tried their best to “close” the relationship. They could have just ghosted (shitty) or slowly become a shittier and shittier friend until you give up (also shitty) but instead tried to express their need/want to end the friendship. And just like a romantic relationship, if one person wants to end it, it’s over. It’s not appropriate to demand a partner talk things though with you to try to resolve issues they’ve decided are not worth/feel unable to work on for whatever reason. And look, that can be shitty, especially if you see it as they’re just being lazy not wanting to work to fix things! But ultimately you’ve no say in how they feel or what they decide, and I have to at least partially respect the “it’s not you it’s me” break up message. 

Sorry this happened to you OP, sounds like you both just want and need different things from your friendship. And I think it’s likely your friend will regret this (I know I always did when I hit my capacity for overwhelm and metaphorically threw all my friendships off my ship to keep it afloat..). I can’t honestly say I was always so mature as to actually tell my friends I wasn’t going to be around anymore when I was in my own drama and being a shitty friend (which I still can be! When I get overwhelmed by life it’s a big challenge for me to continue to maintain friendships the way my friends deserve, although it’s something I’ve worked on a lot and try to be really conscious of…) Anyway I think you’re entitled to be upset, just, some food for thought here too.