Uncontrolled Balance Issue

are causing me to walk into things, etc. I also am having trouble with putting words together. ie I can't think of a certain word while forming the sentence.  I am on some pretty heavy pain meds due to a spinal injury and think the confusion is part of the med effect.  But the imbalance came out of nowhere!
My spinal health background:  Fusion at L3-4. L4-5 (Feb 2010) *this was my final surgery after 2 previous failed laminectomies
Neurostimulator inplanted in lumbar spine - Nov 2010.
Other issues:  I have a growth on the side of my right skull in the temple area. I had it checked out about 3 years ago and was told it was probably calsification and nothing to worry about.  It has continued to grow (outward) to the size of a Pecan shell.  Could this be what is causing the imbalance or the spinal issues?  Or something all together different?
  What is a good neuro test I could perform on myself to see if this is neuro positive?
  Thank you in advance for your response.  I don't have the money to seek my PCP at this time since I just got out of hospital with pneumonia last month.  But, if it's something I should be checking into, then I guess I would need to go to the PCP.
Let me know your opinion.
Thank you!