I’m so sorry to hear about the death of your parents. There is no set time line on grief, but bottling up feelings and not being able to talk about it can certainly be a factor that causes more problems further down the line. I’m glad that you’ve found this site and started to share things here - it is never too late to open up and get some support.
I can understand not wanting to cause your fiance stress, but if he feels that you are shutting him out, that might not be good for him either. Have you considered looking into any counselling? It could be helpful to have a neutral person to talk through the issues without overburdening your fiance.
While you wait for more replies to your post, I thought you might be interested to know that we have had another user called @DanM11 join recently who has posted about the death of his dad in 2005 and how it was many years before he was able to grieve properly. You can read and reply to Dan’s post here.