First of all, you should not lose your data if you properly back up - which you ought to be doing all along ;-)
You can zip your entire project directory and all the files in it to another location outside of the OT directory to secure your hard work before doing anything else.
Question: Are you able to take a simple 2 or 3 frame test animation and export that? If not, then yes, in all likelihood you have an installation/configuration issue.
Otherwise, if that small test goes through, the issue may be more about insufficient memory than installation.
The solution here would be to break your animation into smaller chunks. Export each, and then reassemble them using a video editing proram.
Hope some of this helps - or that a more knowledgeable response comes soon from someone else.