My gerbil's death seems to effect my other gerbil...:/?

Gerbils are very social creatures and having only one gerbil can and will make a gerbil depressed, sad, and lonely. even aggressive so it is wisely adviced to get Harley another friend asap. Now, since males are tolerant with other males you MAY be able to put in another male without there being fighting but if there is, separate them immediantly and use the split cage method which is basically getting a 10-20 gallon tank and splitting it corner to corner with wire mesh. put 1 on 1 side the other on the other side and every few hours, switch the side they are so they get used to each others scent and company. do this for a few weeks or until they start sleeping next to each other through the mesh or trying to groom each other and they arent scenting frantically. (: