I’d say there is a nuance:
“En passer par là” implies that you need to go through something unpleasant to achieve a goal.
‘En arriver là” implies that you have to resort to some drastic measure to achieve a goal.
A common variation of “en arriver là” is “en arriver à de telles extrémités” but in this case the drastic measure aforementioned is already known to your interlocutor.

Here is an André Gide excerpt from Retour de l’U.R.S.S, Retouches à mon retour de l’U.R.S.S. that shows the nuance is slight but exists between both expressions.

Car pour eux il ne s’agit pas seulement de montrer comment on en est arrivé là (ce qui est, somme toute, assez facile à comprendre) mais de prouver qu’on a raison d’en arriver là, ou du moins d’en passer par là, d’abord et en attendant mieux…

However, in your particular sentence, both idioms are close enough for being equally usable.