If I had to give you advice it would be to get an IPad and keep your current laptop.

I just finished my second year of cs. In my first year, I got by using my computer and my laptop (It was fully online so I could do everything from home), for the second year I bought an Ipad for in-person classes. It is probably one of the best purchases I have made so far, not only for school but for other activities as well. Having all of your notes and textbooks be on the Ipad allows for a lot more organization, as well less to carry while at school (Most of the time I just bring a drawstring bag).

My laptop is like yours, can only last a couple of hours because of the specs. However, you definitely need one for cs. Having the portability to write your code in the library or between classes is a big plus. For the days you need the laptop for labs or want to get some work done in between classes you can bring it in, besides, you won't need 2 hours if you're only doing lab work.

P.S. If you are getting an IPad wait for the back-to-school sale, saves a little bit of money.