...[she] generally doesn't seem to care all that much if I exist at the minute.

Those last three words... at the minute. At the moment. Right now. However you say it, this is temporary (for now. This can change.)

As @David Thornley stated, you're the adult in this relationship. I'm not going to tell you that your feelings aren't acceptable. Feelings are feelings, and we have them. Whether they're acceptable or not doesn't really matter; what matters is how we deal with them.

Toddlers/2 year olds more or less wear their feelings on their sleeves. They aren't good yet at hiding them or maintaining a sophisticated pretense.* So, yes, right now - for the moment - your daughter has withdrawn from you to a degree for some reason she probably can't express. And you're feeling hurt.

What to do? Accept that your daughter's feelings are as valid as your own, and know that they are based on the understanding and reasoning capacity of a 2 year old. While an adult might understand that you losing your shit (as you say) is due to fear/stress/being overwhelmed, a 2 year old doesn't. If this episode immediately preceded her change towards you, you can safely chalk it up to that.

She is a small child wholly dependent on your wife and you for everything, including her feelings of safety and being loved. Depending on how you behaved (I'll assume the worst), she may have felt fearful and in danger from you (not the stairs or the situation, as you were.) You scared her. She's not odd for withdrawing to the safety of the parent who (at the moment) is "safer" to her.

Your responsibility now is to make her feel safe again with you. The trust you had before will take a bit of time to rebuild, but 2 year olds are pretty forgiving. It's probably too late to apologize to her now, but be consistently kind, loving, patient, and respectful with her, and she'll come around.

...is there light at the end of the tunnel? Will this pass? Can anyone lend advice on how to best deal with it.

Yes, I guarantee you that if you are consistently kind, patient, loving and respectful towards her, she will love you again as much as she did before. And, if your wife angers/frustrates/frightens her enough, she will probably prefer your company over your wife's.

*_{They can and do pretend, though. Just not for long periods, i.e. hours or days.}

_{N.B. I'm assuming you became angry on the stairs; please ignore if that was not the case. To elaborate a bit so you can understand how valid her feelings are: in a moment of fear, you made her responsible for feelings you found difficult to handle. Fear is a primary emotion. It's painful and hard to handle, so it often quickly changes to an emotion which is easier to deal with: anger. Anger is outwardly directed, so easier for a person to handle, but it is viewed as a threatening behavior by viewers, especially when the angry person is looking directly at the viewer.}

_{Witnessing fear does not do the same thing to the viewer, nor does witnessing anger while the gaze is averted. While it might still frighten your daughter to read fear on your face, it's not nearly as frightening as expressions of anger directed towards her. Fear can actually draw a person closer (you become fearful together).}

_{Imagine the difference in reactions to a toddler (or a child) in the following scenario(s): a child runs into a street with traffic. Scared out of your wits, you run out and grab them. You a) shout at them angrily, saying, "Why did you do that, don't you know how dangerous that is? Don't ever do that again!", or b) you hug them, say, "Thank God you're safe! Please, don't ever do that again, I would be so sad if you got hurt!"}

_{The difference matters. Strive for the second. But if you must get angry, shout at the stairs, not her (Damn stairs! Why are you here?) So what if you feel stupid doing so? Her feelings come first.}

_{The informative value of emotional expressions: ‘social referencing’ in mother–child pretense
The Effects of Fear and Anger Facial Expressions on Approach- and Avoidance-Related Behaviors.
Effects of Gaze on Amygdala Sensitivity to Anger and Fear Faces}