I know of people who have gone to their gp when dealing with grief. For instance if you are not sleeping then they can help you with that.. Or in some cases, referral to a counsellor or therapist is necessary
No one will ever get it. You will not get it when they are bereaved because your grief will be different to theirs
If you can grieve in private, that's ok. If you have one or two people you can offload to, that's better. You are not obliged to tell everyone how you are feeling. They are not obliged to understand. even if they wanted to they probably couldn't because we are different
I do agree that people not getting it and coming out with insensitive/offensive nonsense in response does feel worse than keeping it to yourself. It's isolating and lonely and incredibly hurtful and painful.
But then long term pretending to be ok just breaks you. This is still the path I pick since that first bereavement. People are shit with grief, and dealing with some of their shitty comments was much worse than being alone.
Ideally, it's about finding people you can be not ok with who won't be dicks in response.
There are bereavement counselling/support services your GP might be able to refer/signpost you to who might be helpful?
Samaritans / online communities can also be a bit better - especially if you can connect with people who've suffered similar losses where you may relate more and be able to offer mutual support/understanding even if you don't totally get every single bit of their experience and vice versa.
I found it a lot easier to cope and actually started to process my own grief several years later when I finally met people who'd experienced similar kinds of loss to me and did get parts of it in ways nobody else around me had until then.
Because even if you don't get it entirely, it means you can actually have a meaningful conversation about it at last - where you feel understood and you understand them, and nobody comes out with offensive bullshit.