you will be covered with your UE citizenship, have you an EE11 card from the UK or proof of social security coverage from UK? You show that and you should be covered.
I get it from France when there for my kids and now there is a CEAM in english its the European health insurance card, your UK social security office issued it.
Otherwise go to the nearest health office you have at centro de servicios sociales Gallur right there in Laguna at CALLE GALLUR, 24 metro Laguna.
They should be able to direct you or help you better;hope it helps