Ending a long-time friendship

Hi everyone! Recently I've been thinking about breaking up with my long-time best friend. We've known each other for 13 years and she is the only person whom I consider my true friend. I'm not a very sociable person and I don't let people into my life easily. Besides, the overwhelming majority of people whom I've considered friends in the course of my life forgot me and disappeared from my life completely. So I've always felt grateful to my friend for sticking with me for so long. However, I couldn't help but notice that we became way too different. As much as I wreck my brains trying to think of anything that unites us, I can't come up with a single thing. We have different interests and priorities in life. This is the first red flag. The second is the behaviour of my friend. This May I lost the job that I really liked and had good opportunities of career growth in. After this I plunged into severe depression, spent 2 months in therapy, went to various doctors. During this time there were days when I desperately needed support. My friend tried to cheer me up via texts sometimes as she was working and didn't have much time for meeting in person. (These attempts seemed kind of lame to me, not gonna lie, but it's better than nothing.) One time, when we were planning on finally hanging out, she ditched me in favour of going on a drinking spree with her other friends. When I told her how hurt I was by this, she justified it by saying that she wanted to drink and I wouldn't agree to it. I'm not all that against alcohol, I can have a drink or two sometimes, but I've never in 25 years of my life got drunk and I don't condone such mindless drinking, especially when there's no premise for it. In general, I like spending my free time going to museums, exhibitions, excursions or just going for a walk in a park or around the places I find interesting. While my friend likes drinking booze in quantities far from modest and doing stupid shit that makes me cringe. This, in her opinion, is the epitome of a perfect pastime. And a perfect place to live, according to her, is somewhere with a lot of shops to buy various booze in and with lots of like-minded "fun" people to drink with and do stupid cringy stuff. Another thing is her obvious selfishness. She's so self-entitled that she always makes everything about herself. Whenever I share my mental problems with her, she immediately starts telling about herself, how she handled this or that situation that isn't even related to the topic in question. Quite frequently over the course of this summer she noted how busy she was with work. Don't get me wrong, I'm perfectly aware of how hard she's working and I'm genuinely proud of how much she's achieved at work. But more often than not she talks about this in such a bragging-like manner, as if saying "look, I have a job and I'm making quite a lot of money and you're doing nothing". A couple of days ago I came back from my one-week trip to the city that I really like visiting. I planned this as a continuation of my therapy, as a way to consolidate the progress I've made in fighting depression. And when I told my friend about my experience, she replied, quote, "I'm glad you've had such a great trip! I'd also like to go away somewhere but I have SO MUCH work right now". And right after that she sends me voicemails of about 8 minutes (she's always been a girl of many, MANY words) telling about how busy she is and how much money she makes. It sounded a lot like "while you were resting, I was grinding". Well, it wasn't like I lost my job on purpose! And it wasn't like I was so lazy I didn't even try looking for a new job - it was because I was so depressed that for months I struggled with such simple things as getting out of bed in the morning. Don't I deserve at least something good in my life after months of living in total darkness? Why make everything about oneself? Why not just say something neutral like "it's cool that you've had a great time" and let it be? Why shove something that I lost, that wasn't even my fault, right in my face and make me feel dejected and guilty? Anyway, I feel bad in this relationship and I'm tired of it. There's no point on holding on to something that's not working just because of its duration. Time passes and people change. Surely, it'd be sad to lose the only true friend I've had, but I feel it's time to let go. Besides, I'm fine by my own - it gives me time to think about myself and sort things out. And who knows, maybe some day I'll meet people who will become my close friends. I'm wondering what you guys think about my situation and what you would've done in my place. Should I really end it? And if yes, then how? Currently I have no better ideas than just not texting/calling or communicating as little as possible so that it'll eventually fade away. Thanks to anyone who's read this long post to the end! I really appreciate it :)