Possible tranny damage?

Update on this,

Finally had time to finish bending the cooler lines into shape and refilling the tranny with atf. Also got the brake lines finished so I can actually drive it again. Here's the current situation, all gears work and it moves again, but when shifting into gear (drive or reverse) from park/neutral, it slams hard. Like, hard enough to rock the car and jolt me a bit, makes an audible clunk as well.