You don't need to spend a fortune to keep warm. Your wind breaker and hoody are good starts. I would start with a thin layer consisting of long underwear and long undershirt, tight fitting to the body. Then your hoody and windbreaker. I would carry your shirt in what every you carry your stuff in. This needs to stay dry and not stink during the day. Put it on when you get to school. When you get to school turn your hoody inside out to dry quicker and let the moisture escape.
On really cold days add another layer. I am not convinced you need to by anything that you posted links to. I think the RPM jacket is going to keep all moisture in, the Firewall jacket could work but is too form fitting unless you buy a larger size. You need to be able to fit a layer underneath. The Elite Barrier jacket could work but you kind of already have a hoody and windbreaker why duplicate things. Try what you have before buying something. The balaclava is a good idea and you need a great pair of gloves.
In time you will get use to riding in cold and miserable conditions and won't think twice.