Buffy, very sorry to hear about your loss, but I don't think what you're experiencing is particularly abnormal, especially if the loss was unexpected or you weren't prepared for it.

Unfortunately it's also normal to go through ups and downs when you've lost someone close and sometimes it's important to let the grieving process naturally take its course to allow you to move on healthily. Always remember though, if you feel this way about the person you've lost, they must have lived a valuable life to be loved so much. Cherish that you had the pleasure of this person being part of your life.