Sidewalks are for walking. I would only use them if the road was really bad and I was only going a short distance. 5 miles is too long on sidewalks. You would have to speed down alot to ride safely on sidewalks and it would take you ages to reach university.

So you should use the road. Can you give a screenshot of the typical road on your route? Like with google map?

Now how should you ride on the road? There are different oppinions on this. Alot of "cycle activists" here will tell you to take the lane. I would strongly advise that you don't. In the real world, most cyclists don't take the lane.

In my experience taking the lane will provoke angry drivers and dangerous driving. Stick to the far side of the road. Try to stay as still as possible and take up as little space as possible to make it easier for faster vehicles to get past you. I think this will make you feel much safer than riding in the middle of traffic surrounded by much larger and much faster vehicles constantly holding up behind you waiting for the slightest opputunity to dangerously accelerate past you.

Maybe also find a different route and stay away from main roads with high levels of traffic. I enjoy cycling the most when I'm on side roads, even if its a longer route.