(((((((((Fifth_Sonata))))))))))
First, BREATHE. It will be okay. It's scary to admit you need any sort of help. Especially when going to a health centre on campus ... I remember the first time I went, and that was nerve-wracking. I didn't have to fill in any sort of intake form so I can't help you there, but how about you include the SI anyways. They're not going to try to send you away unless you're clearly trying to endanger your life. SI isn't that. They can try to make you sign a contract, but that's about as far as they can go. Just go there to talk to them. See what whomever you get has to say. If you don't seem to connect with one person, ask to be referred to someone else. It has to be a good fit for you, working through emotional stuff is hard work. Well worth it, but it can be hard. (That's not to scare you BTW). If it helps, write down everything you think they might need to know to help you (all that you're willing to share) and bring it to the appointment with you. They'll ask a lot of questions, probably ask you "why you're here" and then they'll just let you talk. Take it easy on yourself, it's hard to just "trust" another person with our stuff on the first try, so if you can't say much then that is OK.
You'll be fine, but please let us know how it goes. Good for you for making the first step. It's a hard one, so I commend you on your bravery.
Take care of YOU.