Stop letting those thoughts take up space in your head. Nobody will ever care about you if you don't care first. If you tell yourself you are worthless then you will always be treated as such.

I can feel similarly. I have people that love me but I've had a lot of people leave me. I've often been treated by others in my childhood as a ghost. I was invisible even tho I tried to stand out but the effort did not result. I was just invisible and so I became invisible.
However I prefer to have genuine connections and of I have to walk a lonely path to find the right people then so be it. I prefer friends who actually give a crap about me then those who use me for fun but will leave me hanging last minute.