As you have already seen the support and feedback you get from this forum is great, its helped me alot when ive become confused or uncertain about certain foods, supplements etc i should/ should not be taken.
But like a lot of people have said everyone is completely different so the answers you are going to get are mixed and at the end of the day its what suits you.
Reading your first post felt like i was looking at my own first post, no one in my family with it, healthy i was at college in the UK but also playing semi pro football (soccer) and as im english of course i loved to binge drink (still do when im not flaring tut tut).
What ive learnt is dont sit there and re trace your steps of how this happened to you because you will go mad way i look at it its just in your genetics you never know some where down the line a distant relative had it could be anything.
Regarding the protein thats got to be a load of bullcrap, most of my mates are into body building and i think all they have is protein lol so if we went on the theory to much protein gave you the UC then surely every body builder in the world would have it. she just saw you where into the gym and take a lot of protein and thought she was being smart and made that the reason.
Protein heals the body it doesnt make it worse. an interesting theory i have been researching lately is supplementing Amino acid, do a google search apparently there are positive effects with UC.
Tips i would give you are stay away from red meat especially lamb, caffeine so any sports drinks tea or coffee, greasy foods such as fast foods and for sure stay away from creatine it goes straight through me.
I have had to take a break from playing football because for some reason playing competitively gives me the worst D i think its a mix of anxiety and nerves, i remember before i had UC the morning before a game i would be on the toilet about 3 or 4 times now its double that lol.
still hammer the gym though and one bonus of having UC is you can still put muscle on but your body fat drops right down so it makes you look shredded lol always look on the bright side!
Hope this helps