What Causes Blurred Vision And High Heart Rate Post Chemotherapy?

I am a 65 yo female cancer patient with Mantle cell NHL for the past 3 years. I am in remission but I received spinal injections for several months and now maintenance chemo every 2 months. A test result said I am at risk for brain cancer. Three weeks ago I received injections in my neck and hips for pain which worked well. The pain returned to my hips and my ligaments in my legs draw sometimes. The past week my vision has been somewhat blurry and today my heart raced, I felt like my head was under a lot of pressure and had to go to my knees because I felt I was going to black out. I still feel as if something is wrong . I got a flu shot a month ago also with no reaction. What does this sound like to you? I am going on vacation in 2 weeks and am afraid if I tell my cancer doctor he wont let me go.