The first thing to remember is you’re studying and living in Spain. You’ll get so much more out of your degree, the university experience and your life, in general, in Spain if you can speak Spanish to a reasonable level. The time and effort you spend learning Spanish is well worth it, so we strongly recommend setting aside some time to learning Spanish every week.
However, it’s also true that if you are enrolled on a bilingual degree and your degree requires you to undertake practical training in Spanish (e.g. Veterinary Medicine, Dentistry, Physiotherapy, etc.), then you will need to learn Spanish and, in most cases, demonstrate a B1 level of Spanish at some stage before you can graduate, but some degrees have other requirements. When exactly you will need to demonstrate that you possess the required level will depend on the degree you are studying. Ask your Spanish teacher or go to the section for your degree of the University website for more specific details.