So sorry to hear that, Kay.
That kind of a loss is a major one...
It will take a while to come to any terms with.
It's also normal to feel detached & like nothing makes sense followed big losses like that, so I get it might be extra hells on you.
Remember it's a feeling.
You are not lost.
You are not changed.
You aren't uprooted with no returns.
The person was lost, the relationship and some part of you that was with them. Some. Not all. All the rest of you is still there & will be felt when grieving and the surreality of it all passes.
The world of your relationships changed... there is a very real void there, now - but it won't be forever.
Some loss gets better with time and distance.
Other with therapy & working on own goals / new life.
Other with finding someone new.
Other with grieving it over.
And some pieces never do...
But even these make people who they are. Life they lived.
Also... Reach out.
To everyone & anyone you can.
Don't stop reaching out.
Don't close it inside and be alone with it. Talk to people about how you are. Even if talking gets tiresome or you don't feel related to or understood... talk up still.
And find what you used to love before the relationship, and what you always loved and never had enough time for within it... and do those. ;)
You aren't less you.
You are fully & totally you...
Who lost someone they love.