I would be happy to help assist you in understanding your dream. Sounds as though you have had a spiritual awakening in your life. Being bit on your left finger is showing how you are being awakened to certain negativity or sin. Black is the color for evil and the darkness "negativity". brownish yellow is showing a mixture of personal feelings and small amount of fear. Treatment for the poison, perhaps seeking guidance in healing. In the beginning of the dream being Jamie from the game of thrones. This dream can relate to the negativity or sin that is being put forth on TV & Movies. It can also be symbolic of the "battle at hand" of good and evil. You are becoming aware of the impact this world has. Choose to be on the army of righteous and you will have your eyes opened even more. If you have anymore questions please feel free to ask.
Yes the dream can relate to your ex gf. It can be the "awakening" of you understanding that she may not be right person for you in the long run. The game of thrones can be showing this battle in your mind of deciphering whether to speak to her again. With how the dream ended. I believe the dream is showing you the thoughts you have are correct towards her. Seems as though she may only bring some more problems in your life that you do not need. This is relating to the part of your dream where you were bit on your left hand. The results will affect your works. I believe you may need to move forward in your life and keep making these right choices.