As you walk, try the '5 things' technique.It's not a 'cure all' but it can help you calm and reduce your anxiety level.
www.urmc.rochester.edu/behavioral-health-partners/bhp-blog/april-2018/5-4-3-2-1-coping-technique-for-anxiety.aspx
5: Acknowledge FIVE things you see around you. It could be a pen, a spot on the ceiling, anything in your surroundings.
4: Acknowledge FOUR things you can touch around you. It could be your hair, a pillow, or the ground under your feet.
3: Acknowledge THREE things you hear. This could be any external sound. If you can hear your belly rumbling that counts! Focus on things you can hear outside of your body.
2: Acknowledge TWO things you can smell. Maybe you are in your office and smell pencil, or maybe you are in your bedroom and smell a pillow. If you need to take a brief walk to find a scent you could smell soap in your bathroom, or nature outside.
1: Acknowledge ONE thing you can taste. What does the inside of your mouth taste like—gum, coffee, or the sandwich from lunch?
Once you are calm, start making your plans to leave. Remember that you don't have to come up with 'absolutes' today. As long as you are not in physical danger, you can move more slowly. Start with 'loose plans' (where to go, how to get there) then start to firm them up (make phone calls, how to pay for tickets, what to pack, etc), then execute them.
And call your mum. Let her know that you've reached your limit. Tell her she doesn't need to rush down, just to be aware that you will be needing housing in the not too distant future.