Should I resubmit my paper to get the attention of a slow reviewer?
This is clearly answered in the comments by @Stephan Kolassa (making community wiki here just to post an answer for the question).

Absolutely do NOT resubmit the paper! If you do, you could end up having everything rejected.

Contact the editors of the journal. 3.5 months is not such a long time for journal review in many fields (unfortunately) but it is sufficient time to warrant a quick friendly email to the editor asking what the progress is. 

Though you should not pester the editor, contacting them after 3.5 months seems perfectly reasonable. But keep a friendly/deferential tone. (Don't demand or complain ... just ask for info.)

(And best of luck with the reviews. The first submission is always the most nerve-wrecking. If it works out, then great. If not, try not to sweat it too much. Rejection happens to nearly everyone.)