Is this doable?

It's quite doable, it's all depends on how discipline you are with your academics. If this is your first time working a job then maybe select an easier course for the summer so you can get use to how things work. What else you can do is balance out the difficult courses and place them with less difficult ones so you're not killing yourself along with work. Other then that go for it! I have done it before and I survived the mayhem

Don't bite more than you can chew. I currently work full time (40 hours a week) and taking only 2 classes(AP1 and English 103) but it's hell. I would go to a CC and just shoot for the pre-requisite, taking them 2 at a time, 2 in summer and 1 in winter. If you are doing a bridge program for the BSN, take those classes during summer or winter. My focus would be those entrance classes to the program.

As far as money goes, I am lucky to be working for a company that pays tuition reimbursement so after those summer and winter classes I go claim my check.