When Psychic Vampires first begin to feed it tends to be spastic and unpredictable. Since it comes so soon after you asking for help with your chains I can not but help feel partially responsible for your current situation. What I can recommend is that you start frequenting areas that have large quantities of people, then you can feed all you want, you'll find that if you stay in one place for 30 min you can get all the energy you need and no one else will ever be the wiser. That or find some one you do not like and make up a reason to be near them for a bit. Worry not about the beginning for it is like riding a bike, pretty soon the feeding will become controllable and natural.
What you described sounds very much like what I've seen attached to myself and other vampiric individuals I've met. It is the actual vampire, but it is bound to our spirit/astral body at different points (our chakras), through different parts of ourselves we have allowed it in. When it is particularly hungry and we are not feeding it enough, it can rise of its own will (quite strongly at times), especially if we don't carefully guard our minds and emotions and hearts. We must seek to always learn the truest nature of things, creatures, reality, and life to loosen it's grip upon us, since it feeds of negativity, lies, and deception, it twists and steals our life's energy. We, if there are half-demons, are probably the closest thing to them. Hybrids. Which is why we have our dual thought processes;, one very human and one very predatory and demonic in nature. I also believe that genetics plays a part in activating dormant genetic strands that turn on certain and varying psychic abilities in us, the demonic energy being the catalyst of activation. Learning to love others, oneself, and to cultivate faith, truth, and virtue in yourself is the only way to really weaken or control it. You must stay positive. You are to not become the monster. I feel the creation of art, msic, and other forms of expression help to relieve it some... also, eating food that contains it's full spectrum of nutrients and energy will help energize you. Organic dairy, chocolate, hormone free meats and fruits and vegatables grown organically and minimally processed can really help.Also, thank you- I like my name too. It means, "Luminous," or "Precious Light"
It sounds like you've already been doing what I had advised by breaking chains of bondage around yourself with truth and will. That is a good thing. I've written down conversations I have had with mine.