Yes most things in life and Medicine can get better, get worse or stay the same.
Thanks for both of your replies :)
Since my question I've learned a great deal on this topic (from this site) and have seen an ophthalmologist. So here is what I found out, just in case someone else has been having a similar experience.
My symptoms were not caused by exophoria, it just happened that my exophoria remained unnoticeable (I am not sure why this long, I've had many eye exams) until I experienced severe dry eyes. I wear contact lenses for roughly 10-15 hours a day and do a lot of school work and play games occasionally on my computer (I haven't had any problems for 1.5 years with the contacts). The symptoms started slowly, I had a near unnoticeable light sensitivity for 2 weeks that lead to the severe case of dry eyes. I initially thought the light sensitivity was due to a migraine, I sometimes get the symptoms without the actual migraine/headache. During this time my eyes were at their worst when I got up from sleep or when I spent time on the computer (due to the lack of blinking).
Here are the information I was able to jot down after seeing the ophthalmologist:
1) I was told that since I don't experience double vision when my eye deviates it means that I was born "wired" this way.
2) I was also told that I cannot make this worse or better (the exophoria), any changes to my exophoria will happen regardless of my activities or environment.
This seemed to me a bit contradictory... Isn't wearing prism glasses an example of worsening an exophoria by increasing the likelihood of causing double vision?
3) And lastly, I was told that it is unlikely for me to get double vision (I believe he said till old age) due to the fact that my brain has adapted to suppress the deviating eye.
Most of what I've learned has been from this forum and I hope this post can be useful to someone! :)