First and foremost: you are not a failure. Nor are these your actual GCSE results, and even if they were, it wouldn't be the end of the world. There are multiple different paths you could take. Don't worry
I'd recommend being honest with your parents. If they're making you overly-stressed with their expectations, then tell them that, and seek their support. I know moving schools and stuff can be difficult - you can talk to your teachers, form tutor etc. at school if you're worried that your parents won't take your grades well or you think you need mental health support. You can also use childline.
Now, be honest with yourself. (Apart from moving schools), are you not getting the grades you want because you aren't working hard enough at school? Start putting in the effort into lessons now. Are you not revising effectively or enough outside of school? Make yourself a reasonable revision timetable using active recall (i.e. flashcards, brain dumps & essays/exam questions [eventually doing past papers under timed conditions], NOT mindlessly copying out notes) and potentially revise with friends. Are you not motivated enough? Set yourself some short & long term goals to remind yourself of. Are you not understanding the content you're meant to know? Talk to/email your teachers and watch videos on youtube. Are you revising too much to the point you are completely burned out and struggle to begin? Timetable in some more relaxation time and do your hobbies/hang out with friends.
Message me if you want some subject-specific revision advice.
But please don't get too stressed over these results; they don't define you. They can be improved through effort. GCSEs are meant to be difficult (that's why they're a qualification!) so please talk to someone about your mental health if you're struggling - it's not a sign of weakness <3