Is it normal that the tiniest inconveniences make me feel suicidal?

Sorry, it’s quite a long one.

I’m struggling with what everyone keeps telling me is anxiety and depression. I’ve not got a diagnosis because no one I go to will refer me to the appropriate consultants to do so, however if it is as people say I have suffered from anxiety since being around 6 years old (as far as I can remember) and depression for a good 5 years, perhaps longer. I have had existential dread for a good few years as well. I’m nearly 18 years old, I’ve got my entire life ahead of me and if I fight my illnesses I am perfectly capable of getting some decent grades, a decent job and salary and eventually developing my relationship to something more adult that I can settle down into.

However, my brain is telling me that nothing is worth it. I’ve grown up feeling scared of everything, and feeling like everything is ultimately meaningless. While that may make me sound like a fake-deep, pretentious d-head, it’s exhausting. I just want to live without feeling like I’m fighting a losing battle. Logically, I have a keen sense of self-worth, and I know I’ve got as much potential as everyone else. Emotions don’t really listen to logic, and I deal with an overwhelming amount of self doubt and self hate. Every inconvenience feels collosal. A tap on the shoulder feels like a harsh shove to the ground. Instead of brushing it off, my mind immediately reverts back to suicidal ideation. Which, when you’re incredibly irritable due to always being worked up and agitated, leaves you feeling suicidal pretty much constantly.

I’m trying to get help and I’m trying to help myself. But I don’t feel ‘normal’, and I know that’s not a big deal in the grand scheme of things, but it’s very disorientating when you’re trying to keep yourself alive and well and your mind keeps trying to find excuses to kill you.