Thickening the stool can help (inmodium and Metamucil (I like to take several capsules before each meal).
time & patience and talking yourself through holding it
i did a gazillion kegels and then also did biofeedback training-I found that to be beneficial.
MANY years later I discovered a bidet attachment for my toilet seat. It was life changing to eliminate the burning, chaffed skin-can't recommend it enough!
good luck! Congrats on making it thru graduation!