Gear shift won't shift into reverse or park (is in neutral)

I have a 2003 Subaru Forester, automatic transmission. Yesterday, I accidentally left a door ajar and drained the battery. This morning I had my roommate jump the car, but first we had to push it out of the driveway. The gear shifter was stuck in park. I did not realize that there was a release that I could engage with a screwdriver to release it from park, so I muscled it into neural. We jumped the car and everything was fine, but then I could not shift the car back into park (or reverse). I tried then to engage the release, to no avail. I am able to shift the transmission from neutral to drive and to all the lower gears, but cannot go past neutral on the way back up. Help please!