Should I leave for the holidays or not?

I love to travel and I have an oppurtunity to go to Peru during Christmas and I dont know if I should. I need help evaluating the pros and cons.

Pros:
- My friend and her family are visiting her brother who has recently moved there, and I would spend new years and christmas with them at his house in Lima
-As an anthropology-archaeology major Peru has always been the most interesting country and my personal favorite, going to Peru is a dream come true
-I found a pretty cheap plane ticket that I must buy ASAP otherwise it wil be too expensive
-Im going on exchange to a university across the country starting in january, and I would go directly there from Peru, so I have to buy a plane ticket anyway
-I plan on taking a gap year starting in april to do an international internship, volunteer, travel and I could use some travel experience
-although I would like to go Peru during my gap year, its not guaranteed that I will

Cons
-I will miss christmas with my family, and my birthday, which ive never done before, but what is worst is that i wouldnt return home, I would go straight to vancover for four months on an exchange for university and my mom hates that i am going to be away from home for so long, she believes I should live at home until i get married (which I think is psycho, but I dont want to upset her)
-Going to Peru means I would have to leave right after my finals in december, and since my friend and her brother wont be there yet, i will spend the first 10 days there alone, backpacking, which is kinda scary for a 22 year old white female with veeeery little travel experience
-To get the cheap flight, I have to miss the first day of school. I would arrive and have to move in the second day of classes and have the rest of my stuff shipped from home (montreal)
-my health is uncertain right now. I think everything is fine, and I am just suffering from anxiety (i have an anxiety disorder), but I recently had a whole bunch of tests done for really scary diseases and only get the results in three weeks, so i have to book before knowing if i am sick (which I doubt, but still)
- due to the above, altitude sickness and malaria are a concern

So what do i do??? Should I take this oppurtunity to go to Peru or pass it up for now???