Is it possible to have mental problems while on chemo???

r2424243

My dad has stage 4 colon cancer and has been doing chemo for 1 year. He was on Oxyplatin/F5U/Avastin for about 6 months and now is on Avastin/leucovorin/f5u for the past 4 months. He also went thru a breakup. His girlfriend moved out 4 months ago and said it was because he has cancer and it is too hard for HER knowing that he may die at sometime. He has become obsessed with this ex. It is very unhealthy. He wants to talk about his ex constantly and wont talk about anything else. He is on Paxil and xanex. Nothing seems to be working. This is not him. He would never act this way before. He isnt doing anything productive. He isnt cleaning his house, doing any of his hobbies, nothing good. He is seeing a phycologist but that doesnt seem to be helping either! Just wondering if anyone has experienced any of this or have any suggestions.