I’m so sorry to hear about the death of your mum and how it is affecting your relationship with your partner. Anger can be a common response to grief, but obviously it becomes a problem when it starts to cause aggression or relationship issues. It does also sound as lack of support from your partner has added to the problem - grief is a long process and you will continue to need support and comfort for a long time, not just immediately after your loss.
It sounds as though you are feeling very isolated, particularly due to having moved to a new area, and you could really do with some support and someone to talk to. I’m glad that you’ve found this site and I hope that it helps even a little bit to write things down here. You are among people who understand here.
I have found some other posts where people have written about struggling with anger - you might find it helpful to look at these to see what other people’s experiences have been. Some of these are older posts, so the posters might not be active on the site any more, but if you do feel like replying, they would normally get a notification and might return.
Loss and anger
Feeling angry and pointless
Anger
You might also want to consider whether you would benefit from some counselling. Counselling can’t take away your loss, but it can help you deal with your anger and address your relationship problems. Your GP is a good starting point for accessing counselling.
Relate can also offer support with relationship problems.