I lost my game quite a while ago and I decided to get back into the swing of things. So is there anway I can get it back??

No idea, you can change it at Licensing.datarealms.com but I am guessing you mean the cdkey, you could contact data with proof of purchase, but I am not sure what that'd do.
Also, keep it on a disk, that's what I do, and I have only lost a cdkey like, once.

If you're looking to play anything pre-b24, then you can simply use the key and email in this here topic. If you're looking to download the newest version, you'll need to contact support@datarealms.com and work something out with the licensing dude to retrieve your licensing key (which will likely end up as an email sent to your registered email, so if you can't access that then you'll need to specify that as well).