I'm sorry you're going through this @Synne - loneliness isn't necessarily a bad thing though, it's just one of many human emotions. The problem is a society that places emphasis on *always* feeling 'positive' emotions *only* (i.e. happiness) usually does not give us the tools to cope with 'negative' emotions as a result...
I've found the biggest tool in my arsenal has been to become friends with myself. After all, when all is said & done, you alone are all that you have when both entering & leaving this world ...& that's not a bad thing either! Like @rachy said, feeling like there's no one like you.. well, there isn't! Finding like-minded communities helps, but you yourself are unique. If no one helps you... well, help from others is a bonus but the one constant that will always be there is yourself - why not use that to your advantage? No one to connect with... well, I don't know about you but, I find that I can't connect all that well with people when I'm feeling disconnected from myself. You need to put yourself first before you can help others - a little healthy 'selfishness'
As someone with *likely* C-PTSD (as told by a therapist, with whom I am working through it - since the UK unfortunately requires a psychiatrist for official diagnosis, but that's a rant for another day lol), I also recommend 'The Body Keeps Score'. Reading that book was life-changing for me (& I don't use that term lightly!)
Know that it is not you that is the 'problem' - whatever coping strategies you learnt as a child were developed from a limited repertoire. You can't be mad at a child for making do with what they had! But, now that you're an adult, you *can* instead work on expanding that repertoire, to help that inner child with tools not previously available to them It will take time (so don't get mad at your adult self for not being able to build Rome in a day), but that's what the internet is for - we're all in this together