[Help] Staying away from home and my usually very controllable anxiety is now taking over

Background: 19f. No medication. Usually I experience anxiety during new situations (starting a new job, going somewhere new on my own etc). My anxiety usually presents as sweats, sometimes chest pain/difficulty breathing, nausea. Mainly however my mind just starts going crazy and I just start to feel a general overwhelming wave of panic. I'm sure a lot of you can relate.

It's important to note that my anxiety is typically well managed. I started a new job four months ago and that set it off (I was vomiting on the way to work and couldn't sleep because I was so anxious about going to work the next day. Funnily enough I absolutely love my job so I can't explain why it made me anxious, perhaps the thought of doing something wrong and getting fired/not fitting in?). I don't have any management techniques (which is why I am here!) but somehow I manage to get through each bad patch. In general, however, I do have a lot of social anxiety. I still freak out daily over arriving to a lecture late/having to meet new people in classes etc. I would love to be able to make friends and be outgoing, but I'm too busy freaking out about sounding/looking stupid or being disliked.

This week I am staying about 530km (330 miles) away from home at a residential school for my distance education course. It is my first time here. It is also my first time being away from home on my own. I have gone on holidays with my boyfriend and it's been fine (my boyfriend has no idea how bad my anxiety really is, mainly because whenever I'm with him my anxiety does not exist), but this is my first time completely alone.

I arrived yesterday afternoon and completely lost it. The university hasn't been very helpful in terms of giving me written information about where to go/how to get there etc, so it's been very much a case of me wandering around trying to find my way. I managed to find my room but could not find a bathroom/showers. I ended up just staying in my room from about 2pm - 9pm because I was having a meltdown wondering how the hell I'm going to get through this when I can't even leave my room to go to the bathroom. After standing with my ear on my door listening for people for about an hour I finally plucked up the courage to go looking for a bathroom. I found one.

I hadn't eaten all day because I'd been travelling, yet I skipped dinner because of my meltdown (which was partially caused by freaking out about having to find the dining hall/figuring out where the buffet and cutlery is etc. with a room full of people to watch me). I was very ill last night from not eating but literally could not get up the courage to go and get dinner. Then I started freaking out that I would get sick and pass out and that would be completely embarrassing (I have low blood sugar usually, it gets really bad when I don't eat).

Anyways this morning I managed to suck it up and make it to breakfast. It wasn't that bad. I just brought my phone and pretended to be completely immersed in texting to distract me from my anxious thoughts. Now that I've been to the dining hall once I think it will be easier to make it there again for lunch/dinner since I know where to go.

Why am I posting? Because I have no idea how to diffuse my anxiety. I have never seen a health professional about it because it's only really started in the last 2-3 years. I always am aware of how stupid I'm being by freaking out about stuff like visiting a bloody dining hall for the first time, but it doesn't do anything to ease my anxiety. If anything it sets me off even worse. My question is, how can I manage it at the time? When I'm freaking out, what should I do to calm myself? I'm just looking for some support and some advice on how to handle this. Anxiety has sort of "crept up" on me, and it's only in the last few months (and after having a complete meltdown last night) that I'm really realising just how much it impacts on my everyday life and how much it has progressed.

I guess I should also add that I would probably class my anxiety as social anxiety. It's people that freak me out. I'm always worried about what people are thinking, if people are watching, if they are talking about me. I crave new friendships but I get so nervous conversing with new people I know I probably come off as reserved, disinterested and maybe even stuck up. I hate that this is how I am, and I want to fix it.

Please help.

EDIT: I just wanted to add that this is actually not my first time away from home on my own. I actually moved out for ~6 months for university two years ago. I guess my anxiety wasn't nearly as bad then because I don't remember struggling this much!