Usual rule is ice initially to stop the internal bleeding and therefore reduce internal damage and swelling.
Next day use heat packs

I swear by arnica - cream, massage oil, drops to drink, pillules to chew... made from extracts from the arnica plant it is the best thing I know to reduce internal and/or external bruising. Only rule with it is do not put the cream or oil onto open skin (grazes/cuts)

Wishing you the best with the healing...