Hey Zenx,
really sorry to hear about your troubles.
There is always a balance here - recognizing that your supervisor is very influential shows you have good insight and is very important - you cant upset them. However, if he is really influential, just think how down on you and your career he is going to be if you present nothing to him in your final year!
Completely scrapping your project and coming up with a new theme is NOT something you should be doing on your own without help. Period. Sure, help design your experiments, have ideas on hypotheses, but coming up with a novel and important theme to explore needs a deep and total understanding of your literature.
What is going on here though? Your supervisor says you are not working hard enough? Or does he just not see you? He is going to be a lot more receptive if he gets the impression you are putting the hours in - you are going to have to make yourself more visible! Get in early, stay late, etc. Just so that his impression of you improves. You are going to have to schedule meetings with him more than you are having. Contact him and ask for a meeting in say 3 weeks to discuss some new ideas. Work flat out for those 3 weeks, put together your updated results (even if things didnt work) and compile a plan for your work for him to approve. There is not a supervisor in the country who wouldnt appreciate that kind of approach. If he is busy then, then ask when he would have a few moments to meet.
Once you have a plan and new enthusiasm then sure the above advice about things coming good at the end may happen. But right now, you need a pick me up and a reinjection of love for the project. And for that kick, you are going to need to bite the bullet and blitz it for a few weeks to get him back on board! Go for it!!
S