Does this friend already know that you have issues or is this a "surprise"?
If the friend already knows you have issues, then if you feel like telling her that her stating to "just get over it" hurt your feelings then you should. But sometimes others (NT's) will do/say things to deal with social situations as well and if there were lots of people around she may not have wanted to draw attention to your difference.
If the friend does not know that you have issues, then you'll need to decide if it's worth telling this friend that you have issues. If it is - then maybe you need to have a conversation to let her know that you can get overwhelmed and unable to cope with situations if you don't have an 'escape' but I would tread carefully as many NT's don't like to discuss and reach logical conclusions and having the discussion - if it is outside of her understanding of the world - may be difficult, especially if she is the same age as you. She may not truly be open to understanding your 'difference' if she cannot conceive it existing (does this make sense?)
As to sensory overload, it happens to varying degrees in varying people - simply your aversion to touch may not be enough to place you in that category - so I shall tell you how sensory overload fits me:
Too much light, noise, or stimuli (large groups of people, noisy events, crowds, even our monthly staff meeting where I have to sit in a large room with everyone from the office and soak up lots of information) makes me feel exhausted, gives me a migraine, or makes me unable to cope with decisions (such as grocery shopping - I can get overwhelmed and not be able to figure out what mustard to buy if they don't have the exact bottle I was looking for - even if the only difference is the quantity) so basically I "shut down" and am unable to continue that activity.
I also experience this as extreme sensations ranging from a horrible burning pain if there is a tag in my shirt to only knowing that I am in pain because I am "antsy" and can't sit still. (this is likely more of the Sensory Integration Disorder which can help play a part in sensory overload).
Most of the time I find my aversion to touch is the fact that I cannot control it and sometimes in social situations I find it difficult enough to navigate nuances, facial expressions, tonal changes, etc. that one more thing is really three things too many.
Hope this helps.
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"The whole day went not much to your liking... But the sun will still rise, the sun will still rise... You don't have to be perfect, you don't have to play well, you don't have to fix everything all by yourself" --Holocombe Waller