Steph, You poor honey, you really are upset. I know the "throat closing" feeling, I used to get that before, I think its a type of panic attack.
I have had a lot of family issues in the past and I went to a counsellor and it was the best thing that I ever did, I am such a more together more confident person.
You are probably going through all kinds of emotions at the moment with the move coming up etc but once you get back to Canada I think you should find a counsellor and talk to them.
IBS wise, the stress/depression is not going to help, take a twopronged approach to it and decide that you are going to think positive and make a go of all of this.
Look at yourself, You are a pretty, intelligent girl with a great sense of humour, you are very caring and witty, you have a family that loves you and a boyfriend who adores you, you are moving home to where you want to be and your boyfriend is going with you, you are going back to college, YOU HAVE SO MUCH GOING FOR YOU!
We ALL love you here and are sending bunches and bunches of hugs, look after yourself, take time for yourself, go for walks relax and resolve to sort your head out when you get home.