No motivation to study

You'll be fine. I'm telling you, you can literally revise 4 months before gcses and get all 9s. You probably have no motivation because you have always been a high acheiver(assumption). Here's some tips that helped me with my GCSEs(the lowest I got was two 7s)
For english make midmaps with quotes
for subjects like RE and psychology and geography, have modal answers to each question for every topic and practice past papers
for physics practice using pmt for every topic
For every science subject, complete the end of chapter questions on kerboodle first. After you finish the end of chapter questions, then search for a quiz, after you do the quiz, do exampro or pmt questions then do past papers.
For maths use pearson's workbook, maths genie and do the corbett maths GCSE daily-it really challenges you
And for english language, watch exam question walkthroughs on youtube
Hope it helps!
note: you are very privileged to be taking GCSEs-this is something people in other countries would dream of. Take this opportunity and enjoy learning, as this is something not everybody has the chance to do in their lifetime.