Stop worrying and start studying right now. Get to planning. Trust me.
Plan out your Easter holidays, what you plan to do. Focus on the subjects you find difficult and set goals for yourself.
For example: Monday - 2 practice papers of Maths; Tuesday - Make flashcards for Biology, etc.
Work really hard, if you've left your revision till now you really need to push! I'm in the same position though, which is why I mostly spend most of my days revising, but hey, you and I have got to put in the effort!
And don't worry, you've got a month still until your GCSES. That might sound horrible, but if you sit down for a day and start planning out your goals (as what I said above) for the week then you'll be good. When school starts again you need to put in lots of effort and plan out your week just the same. Revise your content, make sure you've practiced a past paper or two. And use your time wisely! I tell myself that if I have time to browse the internet or watch YouTube I have time to study.