There's more than just one way of being schizoid. One symptom is that people with SPD can to be indifferent to praise and criticism. I would tend to think that rejection would fall under criticism. They are different but have a similar root issue.
It sounds like you have a desire to be with other people but have some struggles revolving around that which results in social isolation. Typically, people with SPD will go out of their way to avoid socialization. They don't want it. The rejection would more likely be a relief. From my limited understanding, anyway.
Is your doctor a psychiatrist? I'm guessing so since he knows what SPD even is lol. Talk to him about your concerns and see what he says. He'll have his reasons for his thoughts and will know your situation and symptoms as well as what the disorder is much better.