Ny head is heavy, when i walk my feet are weak, and i lose my balance, and i get dizzy. i am a male that is 76 years old and take the medicine for a-phib. i also had a heart attack fourteen years ago and a light stroke 2 yers ago. the doctors give me warfarin so i don't have another stroke. Are these side affects i am getting from the medine? please write back with advice. thank you.