i used to have this. of course, your depressed feelings come from your depressive thoughts and beliefs. it is only normal that you feel that way when you believe what you believe.
however, its not true. they are not unattainble. yes, you will not have all of them, nor will anyone else. but you can be with some attractive girls in your life. some girls will just like you, and some of them will be attractive to you.
how do i know? because i went through it. i felt the same way as you, i had the same thoughts. i now see a girl who i would previously think of as "unattainble". she is very much a normal person besiders being attractive.
basically all during my late 20s to early 30s i didnt see any girls at all, ever. earlier in my life, i did have some opportunities, sometimes even with very attractice girls. but somehow, i completely forgot about that. i started to firmly believe that i was entirely hopeless. besides, even back then i didnt get with most of them. not because it couldnt, but because i didnt truly believe that it was possible.
so, whats my point? its all in your head. the ants thoughts have constructed a reality around you made of lies. but because you currently believe it, it is your reality and things work out that way. as you dismantle the lies one by one and stop believing them, so changes your reality.
the first step might be to start believing what is actually true on a rational level. the truth in this particular subject is that you can actually be with girls like that, pretty much no matter who you are.
dont believe me? look up "torso guy" on youtube. this guy was born without arms and legs. among many other things, he has a hot wife.