My mum's dead but I can't seem to accept it.?

My mum ped away 2 years ago, and when I repeat to myself that she is gone it just doesn't feel real. And when I see a picture of her it really reinforced the surrealness of the situation. And I accept that she is gone, but it feels unreal. Is there something wrong with me, is this reaction normal, should I see someone about it. Anything would be good. Please help. Thanks