This is a big loss for you and you are going through the grieving process. Do not beat yourself up about it but explain to your fiancé how you feel about going through menopause at such a young age. This is a time in which you need the support of your fiancé and friends and I am sure they want to help but may not know what to say. Marriage consists of good as well as bad times and this is the time that you really need to communicate your feelings. If you are finding that you can't handle the depression, speak with your doctor and he/she can probably refer a therapist that can help you and your fiancé during such a tough time. I am so sorry this has happened to you but I bet you have a good guy who wants to be there for you.