I was on the same boat as you but with much practice and much help, I've fallen in love with chemistry. the way I did it was I read the textbook page by page, anything I didn't understand I searched in google or asked here on TSR. I wouldn't move onto the next page until I understood the first one. I revised chapter by chapter. once I understood the chapter I did questions on that chapter. questions are good because they show if you understand or not and also show you where u went wrong. every question I got wrong I researched or asked why it was wrong.
chemistry relies heavily on knowing the basics, make sure you've brushed up on your GCSE knowledge. also don't feel disheartened as many of the members on TSR knows and have seen I come on here daily and ask questions when I don't understand something and everyone is so helpful. don't give up there are plenty of resources I can recommend "the organic chemistry tutor, khan academy, chem guide and snaprevise"
best of luck <3