Overwhelmed & feeling constantly sad

Hello, this is my first post on this app. Really not sure where to begin or if this post is even in the correct section? A little background info.... I'm 32, living in London. Originally from Australia but moved to London 9yrs ago. I grew up as an only child and my Mum raised me on her own. I've always been an introvert but I feel like since moving to London and maturing, it has developed me to be a little less introverted. I've been single now coming up to a 1.5yrs, which is crazy to think about because it still feels like my ex and I were still together yesterday. I feel Covid has warped time in so many different ways. My ex and I were together for nearly 6yrs. She's honestly my best friend and I still love her deeply. I miss her everyday and having that special someone to chat and confide in about random things/thoughts. We still keep in touch but I feel she has really moved on with her life. I honestly feel like I've had depression for years. I know I have anxiety in many different forms but I have never been diagnosed with actual depression. Not long after becoming single I talked to my doctor and she suggested CBT which I did for a few weeks. I found it somewhat helpful but to be honest I don't think it really worked for me. I've beeb trying to book a doctors appointment for the past few weeks but because of covid/vaccinations the wait to get an appointment at the moment is utterly crazy. I think my anxiety and depression never really saw full light when I was with my ex, as she knew how to make me happy or bring me into a positive outlook. Since breaking up and moving into a new place I have been totally overwhelmed, lost in life and generally very sad. Covid and restrictions came into the world shortly after becoming single, so the past year or so has been very difficult in trying to meet people/do things. I have very few friends in London and I think that is generally down to my personality (introvert, not having any big passions etc.). I also think I probably relied on my ex too much when I was with her and didn't make an effort to make new friends or meet new people. Anyways, latley I just find myself constantly lost and sad. I have no real direction in life and no major passions I'd love to follow and throw myself into. The past few months I have found myself self harming. Not to an extent to seriously injure myself but just enough to feel hurt. I haven't told anyone I'm doing this because I don't want them to worry. My sleeping has been a total mess and I don't think I've had a proper nights sleep in close to 2yrs, my mind races constantly and I overthink everything, my motivation is completely lacking and it shows in my job (working from home hasn't helped), very lost in life with no direction and very scared of the future and what it holds. I'm not sure what to do or where to turn. I know I need to speak to my doctor but at the moment it seems like thats next to impossible.