You will need to share more of your code to help us help you.
In the meantime consider this reproducible example - first call is a "bad wordcloud" with character included, second is a "good wordcloud" with character removed.
In the process I use the setdiff function from base R to calculate the difference between vector of raw tokens, and a vector of stopwords.
words <- c("dog", "cat", "character", "character")
stopwords <- c("character")
words_mod <- setdiff(words, stopwords)
wordcloud::wordcloud(words) # bad cloud!
wordcloud::wordcloud(words_mod) # good cloud! :)