If you have the piece thats broken out... you can always try to glue it back in... but it will be obvoius. You can also buy cheapy red cellophane just to tape over the hole to make it red again. Honestly, the only way to 100% fix it is to replace the light cover. You can get one by going to a honda dealership and going to the parts counter, but it might take a few days to get in if they dont have it in stock. You can also go to any auto parts store (i dunno where in the world you are, but a store like Napa) and they can probably special order you one. You can also call a wrecker yard (where all the sad totalled cars go to die and be stripped for parts) and try to find one; this will be your cheapest option. The good news is is that 98 civics are super super common and the part should be relativley easy to find, and probably relativley cheap.
If you do get one, they are really easy to replace, inside the trunk there should be some clip or screw in panels where you can access the back of the light. You need to unscrew whatever needs to be unscrewed, separate the lights and fuses from the cover and pull it off from the outside of the car. Then just do the opposite process to replace the cover. It kinda sounds complicated but it should be super easy once you can see it all.
Will your dad really be that mad? It looks like you backed into something that was jutting out... maybe just explain that it was dark or your back window was foggy or something and you just couldnt see the object you hit? An accident is an accident you know what I mean?...
Anyways, I hope i helped you out some, and I wish you luck in finding your part!
