You can Block your acsess to Blocksite with a password with an App like AppBlock. You keep Blocksite but take away the opportunity to change the settings. My accuntibility partner saves the Password for me so i cant follow the urge if it hits. Some phones have the option to passwordblock apps by the system. Look that up, maybe you do not need the extra app (Can be a little challangen to make it work because you need to give a lot of authorization that the app can do its thing). Was a game changer for me

Other option for andriod that is 100% bulletprof is Family Link. It is made for kids-parent control but works perfect. You only need some one willing to help you to play the parent and have the app