site speed

Hi, I am running a website https://www.sharangdhar.com which is struggling with load speed issue. according to google loading score is 30, and loading time is average 19.23sec I discussed this issue with my developer he told me that there is only one solution you have to break your website into three part, by making subdomain please provide us solution regarding that, we think about amp pages but can it affect on wocommers or site please tell us