Actually, in an inverted sort of way, I think you've answered your question.
You believe that you have trouble forming lasting attachments, so this belief tends to create your reality. You might try some empowering aphorisms about yourself, and see if they help.
I do see a couple of things in your chart. With Saturn conjunct sun, you're sort of hard-wired to be very hard on yourself. Others might decide that a potential friendship that doesn't gel is "just one of those things," but you are apt to construe it as somehow your fault, that there is something wrong with you.
With Uranus conjunct sun, it can be hard to develop a consistent sense of self, because the "you" feels like it often changes.
Then you've got an interesting combo of an intense Venus-Pluto conjunct your Scorpio ascendant, while your moon (emotional nature) is more detached, in Aquarius. Possibly some people find you very intense and don't know how to deal with it. Then the ones drawn to your magnetic ascendant don't know what to make of your more circumspect emotional nature. They might feel you give off mixed signals.
The lunar Aquarians I've known generally had lots of friends, but I find them to be emotionally detached. This can be the kind of person with many cordial acquaintances but few really close friends. By choice. Aquarius is a mental air sign, and it wouldn't do well with emotional suffocation.
None of these placements suggests that there is anything intrinsically wrong with you, except that thinking makes it so, and then the self-fulfilling prophecy makes it harder to connect with other people.
Once you can just let yourself be yourself, enjoying the gifts of your more solitary existence, without making them wrong, you may find you've created enough emotional space for other people to join you.