I highly suggest signing up with fetlife.com or another community with BDSM practitioners. Seek out for yourself a caring Master/Mistress. Indeed, your goal is to build a "relationship," but not a sexual one.
No, I'm not joking.
As you talk, let them know about your current lifestyle and that you're looking for someone who can give you small tasks to work on that will slowly ease you out of your shell. If they're not understanding, no worries: move on to the next.
Inform your M about how you got the idea from this thread and how all of the people here would love to watch your story unfold, while offering any additional support you may need. Your M should require you to periodically post updates here.
Again, if you think I'm joking. Just try it. You'd be surprised.
Best of luck, OP.