Welcome Lofty; I think it's natural to still have hurt feelings, anger etc. after a breakup of a relationship. Especially one that is a long term like yours was.

As far as a time frame of what is a healthy amount of grieving, in my opinion no one can give you that. You may want to speak to a mental health professional, so you can work through the feelings in a healthy way and perhaps gain better coping skills. I lived my teens and 20's stuffing my feelings down through work, the gym, etc. etc. eventually those feelings need to be dealt with and it's better to deal with them now then carry that anger, hurt etc. into your next relationship. I hope you find this site supportive.