Scrape sections of text from webpages and count words (ideally, in R)

For a research project, I need to scrape text from webpages. There is a list of 359 webpages. The text on each webpage is divided into sections. I need to count the total number of words in each section and I need to count the number of occurrences of each word in my dictionary per section. Ideally, you would also send me each section in a separate text file. Attached you can find an excel file with the links to the webpages. Each webpage has a table of contents. For example, the first webpage should be divided into the section of text before the table of contents, a section with the header "Prospectus Summary", a section with the header "Summary Financial Data", a section with the header "Risk Factors", and so forth. There are usually around 20 sections. The text on each webpage is between 50 and 180 pages long. The structure of the webpages is very similar but sometimes different sections with different headers exist. The problem I experienced when attempting to scrape the text by sections is that webpages have slightly different structures. A majority of webpages has sections in capital letters with the same name but some webpages have different headers and a slightly different structure. I am also attaching a list of uncertain words. For each word and each section in each prospectus, I need a word count (number of occurrences). The word count should include words in either upper or lower case letters. I am attaching some R code that I used to scrape the entire webpage (not divided into sections) and count the words, in case it is helpful. It would be great to have your code in R so that I could continue to use it. I need the output as soon as possible (by Monday). I would very much appreciate your help and look forward to hearing from you!