You're not in the wrong forum since you're asking about SPD. So you're good. Is it possible you have SPD? I think so. If nothing else it sounds like you can relate to certain aspects of it. I'm guessing you've seen the diagnostic criteria for it since you're asking and have noticed, yourself, that you relate to some degree.

Do you have it? Not even the best psychiatrist could really tell you on a forum (you may already understand that). If you've ever had a chance to see the DSM-IV or V you'll see how big it is. There's a lot of overlap between disorders, so differential diagnosis would be needed from someone who can sit down and talk to you face-to-face.

It sounds like this is affecting your life enough to warrant actually doing that if you so desire. Getting a diagnosis from a qualified professional, I mean.