Idiom request for recommending someone to end their toxic relationship/ friendship with somebody

You might say,

She/he isn't your cross to bear. Ditch him/her/Cut all ties with him/her now or you might regret it for the rest of your life.

bear one's cross and carry one's cross

Fig. to handle or cope with one's burden; to endure one's difficulties. (This is a biblical theme. It is always used figuratively except in the biblical context.) It's a very painful disease, but I'll bear my cross. I can't help you with it. You'll just have to carry your own cross. McGraw-Hill Dictionary of American Idioms and Phrasal Verbs

ditch

: to stop having or using (something you no longer want or need) : to get rid of (something)

: to end a relationship with (someone)

: to get away from (someone you do not want to be with) without saying that you are leaving

(Merriam-Webster)

cut/break (all) ties with (someone)

To end or discontinue a relationship—romantic or otherwise—with someone or some group. Mary cut all ties with her family when she moved to New York City. The government began cutting ties with the war-torn country after its human rights atrocities came to light. Farlex Dictionary of Idioms

[leave] that guy/girl before he/she spells trouble for you