Hi Ixodon,

sorry I don't have any good advice for you. I can just tell you that I'm in a similar situation and even older than you. don't know if that makes you feel any better. I hope so.

I know about feeling stuck with career and like there will be no interesting or somewhat not-horrible job out there for me.
also I didn't have a relationship in a very long time. and although I know that you don't need that for being happy and that they can be very stressful I still feel like a failure because it seems I am interesting to nobody in this world. and also I could use some company.
I've watched really unfriendly people finding partners and they also didn't look like models either and I just can't figure out how it works. when I had relationships (much) earlier in my life it didn't seem that difficult at all.

the feelings that my life is not going to be any better and that everything -even living- is pointless however I have had only since I've experienced depression.

I wouldn't trust those feelings!
they can go away and you may look at things more optimistically in a while.
so if you feel hopeless it doesn't mean that it will be like this forever.