I just swapped out the old strings on my Oscar Schmidt and ive got everything in tune besides my High E. I tune it into E, than play a few notes on it and it keeps dropping back down to a DSHarp. I didnt have this issue 10 minutes ago with the old strings.

It's because new strings haven't been stretched as much as your old ones. You may have to retune all of your strings regularly for the next few hours, it's perfectly normal.

Ive gone through a crazy amount of strings, and never had any that stretched that much in the first 5 minutes. normally its about every hour or so. Your probably right tho.