hey @Boobear31 welcome to the forums!
i'm sorry for your loss, i can imagine how isolating the grieving process can be when you're feeling misunderstood. grief and loss can be experienced in different ways for different people, and there's no 'right' or 'wrong' way of going about it, and there's no time frame too. your feelings, whatever they are, are valid 💙
there are people i've lost that i still think of often and celebrate privately but never say out loud. i wonder if maybe it's the same with your family, perhaps they're not as vocal about how they truly feel? is there something you or your family does to celebrate your mum's birthday?
if you'd like more support or information around managing grief/loss, the service Griefline is a great place to check out. you deserve to be heard and understood.
the forums community is here for you 💙