I am currently working with ggplot2, deseq2, vsn, plotfunctions
You should not need to install packages every time you start an R session. Generally you only have to install packages once for each R version.
However, at the top of your R script you have to load every package, so I would expect that you have several
library() statements at the top of your script. For example:
You don't give much information in your question, so hopefully this is helpful. If this didn't answer your question, please provide more information about what you've tried and what errors you get.