First of all death itself simply isn't anything. But I think that with dying maybe it just depends on what the person is dying from.
I like to think the
feeling of it depends if you found peace with yourself before dying. Like if you know you've done all you can to try to prevent the outcome
(by that i mean tried to get better when you wanted to)
Or if you left notes for people you care about or somewhat care about, kind of giving yourself clarification and peace of mind, letting people know what you've done isn't bad and that you feel better dying by your own hands.
(Warm feeling)
And the cold feeling coming with the fact that you feel hopeless, and really sad and lonesome, like you haven't found peace.
Or more so like you didn't want things to end with you dying so soon but you felt like it was the only way to end your suffering.
Hope that makes sense, this is just my view on the topic.
Sorry if I accidentally offended anyone.