I'm so sorry for your loss! I know when I've lost people close to me I like to just get away by myself for a time and keep my mind/body occupied. Just try as hard as you can to get on the bike and ride; no destination, no time limits. Talk to your daughter and let her know the trouble your having. I bet she'll find time to help.

You are understandably going through some depression; your feeling are perfectly normal and I would say everyone who has lost someone experiences it to some degree. If it doesn't start to get better, don't be afraid to go talk with a professional.