The thing is, most relationships – even with seemingly normal people – can become toxic. We simply can’t get out of the relationship just because it’s toxic. The mean things said probably aren’t what the person really wants to say but more that they are fed by anger and resentment.
In that case, as I’ve noted in other posts, the person has to appeal to the subconscious to really make the other love them because that’s the real problem. As noted, love is not logical.