I wonder how to express that consecutive locution in English. It's not very formal and means more or less "given this" or "considering this"
"Il ne s'est pas excusé pour ce qu'il m'a fait. A partir de là, je considère que notre amitié est finie."
D' abord tu as deux phrases, and these phrases are called in english ''compound sentences'' so you must use a conjunctive adverbs to make one and only one phrase , tu dois relier tes 2 phrases afin d obtenir une seule phrase, so in order to obtain that you must a conjunctive adverbs , the best one would be '' in results'' because as a consequence of what your friend did , your friendship with him is over , as everybody knows about the ''cause/consequence''. and i think the best one would be '' he didn't apologise for what he did to me;in results, our friendship is over. we must also use a semicolon before a conjunctive adverbs, so now i put together the two sentences and make one in final. in conclusion , it always depends on the sentence to translate something. i hope my answer satifies your question .