Strange feeling in the evening intensified by drugs?

For a while now I have had an achy, strange feeling in the evening and into the night that is effected greatly by my pain medication. I am 33 years old andI have had several failed back surgeries and am a chronic pain patient, but this has been going on for longer than the back pain. I get bad aches and pains, mainly in my legs which is intensified by the nerve pain from my failed back surgeries, and then I take methadone or Marinol (synthetic THC) and I get very loopy. I often feel nothing from the Marinol except these evenings when I have this strange feeling. On these evenings I have an intensely high feeling and I stumble on my words. It is only certain evenings this happens but it seems worse in the Winter when the weather is cold, although it happens all times of the year.