There are several ways in which your phone can help you access support.
You can call university support services (usually during office hours) or local and national charities (often 24/7 or out-of-hours). Your university website will have a list of local and national charities including their contact details.
There are also charities, such as Shout, that offer a textline. If you are in distress you can text and someone will reply 24/7. You can text them on 85258.
Finally, there are numerous apps available to download that help you look after your health and wellbeing. For example, SAM is an app which helps you manage social anxiety.