@KennyR
Sorry to hear of your loss.
I never really owned a pet so I can't even begin to understand how much you can get attached to them and how much you miss their presence.
If I think about it the main reason I never owned one is because of the fear of not being able to look after it properly. I would find the responsibility too much to handle.
I really admire those that have the nerve to own one and care for it.
Don't feel guilty. The fact that you are greiving shows that you cared for it. It probably had a much better life than many others. I am sure it appreciated that in it's lifetime.