First of all, keep telling yourself it’s just “blah blah blah”, as you call it. Now what do you tell the other person, if anything?
Each person is different and every person is different in their character traits, but my general advice is – if you can – “grin and bear it”. You know you are a good person. Your friends know it. What more do you need? Ignoring the insults may be difficult to do but it can actually be a sign of strength and a way to avoid additional “problems”.
In addition the Torah teaches that one who does not respond to insults has a very elevated soul and is rewarded for controlling the urge to trade insult for insult.
Our Sages teach that "They who suffer shame and do not shame others, who bear insult and do not respond, who perform mitzvot with love and rejoice in their suffering, about them it is written 'Those who love God are like the sun going forth with all its power' (Judges 5:31)."
This verse contains the closing words of the Prophetess Debora after victory over the Canaanites. The message that our Sages convey is that one should not take insults to heart and that one should accept any suffering as a gift from God to atone for sins.
Of course, if you can avoid the insulting person in the first place that would almost certainly be the best course of action.
