This scenario interests me. Although you did not follow any structured rites for invocation, you wound up with unwanted activity following it. I have no intention of telling you that this is all in your head, or that you are a mental case. I also am not going to tell you that you are possessed or have demon activity, since I do not believe in "demons" per-se. There are indeed negative entities/energies that are non-human in nature, and you may have drawn something like that toward you, due to the combining factors of you imploring them for help and being under physical/emotional/mental stress. It's too bad that so many people have to learn their lesson against dabbling in spell casting this way.
Your seeing a physician to help rule out physical causes was a good decision. Now that you are taking steps toward resolution in that area, you can begin to look at this from a more esoteric viewpoint. I would advise against seeking out assistance from priests, shamans, etc. until you take a few steps toward healing yourself. Yes, I said healing. You have enveloped yourself in a blanket of negativity due to your attempt at spell casting and the numerous stresses in your everyday life. Your first order of business needs to be surrounding yourself with a positive, healing energy to combat and dispel the negative.
Pick up some white sage smudge sticks (sage banishes negative energy) and use the smoke to clear each room of your home. Surround yourself with the smoke while you are doing so. Repeat out loud as you pass through your rooms "no negative energy is welcome here. return to your place of origin." You do not need to invoke anything else while you are doing this. Just simply tell the negativity that it is not wanted and to leave.
After cleansing with the sage, meditation is an excellent idea. If you have not tried meditation before, you may want to pick up a CD of meditation enhancing music to help you relax and center yourself. Most new age stores will have previews of most of the music available for review prior to purchase. Make sure you choose something that makes you feel comfortable and completely at ease, regardless of what the salesperson tells you. Different people will respond to different music. Sit in a quiet room by yourself in a comfortable position. Don't lie down, as you may fall asleep. Close your eyes, and breathe in a controlled steady manner. Try to picture yourself sitting there in your mind. Now invision yourself being surrounded by a glowing golden light. This is the light of love and harmony. No negativity can penetrate this light. Feel the light penetrating your skin and flowing through you. This will not happen immediately. Be patient, stay relaxed, and let things progress naturally. As this light flows through you, it is releasing tension and negativity and allowing it leave you and your surroundings. While you are meditating, the burning of incense can be helpful. Some varieties of incense that are used for healing, tension reduction, and negativity removal are: amber powder, cedar leaf, clove, frankincense, juniper leaf, myrrh resin, and tuberose. Of course what you are able to purchase would depend on what your store carries, however all of these are available online as well.
Do not expect miracles to happen overnight when trying to heal yourself. It may take a few sessions of meditation to truly start to feel the negativity release you. If after trying these techniques several times you find that things are not improving, or for some reason worsening, you will need to seek professional help to rid yourself of the energy.
Do not for any reason attempt to conduct further rituals on your own. Meditation is simply using the power of your own mind to heal yourself, has no otherworldly influence, and is safe to do as long as you have first protected yourself with the sage cleansing.
I sincerely hope that this helps you, and that you are able to find peace. Please let us know. Not everyone thinks you are crazy.