Things will get better - honest. Your pain is very raw at the moment, that's very evident.
Keep talking about it, remember the good times AND the bad, make sure your other little kittie feels loved, it'll be good for the both of you to take comfort in the remaining cat.
Keep coming back please - we'd like to know how you're getting on, and when you feel like it, tell us a little more about Himmy and yourself.
Be strong and good luck.