Can you clarify--do you really mean to say that you have horrible wi-fi, or horrible cell signal? Bad wi-fi has more to do with the speed of your home's broadband connection, as well as the quality and features of your wi-fi router.
If that's the case, and if there's no way for you to get either a better broadband connection or a better router, then using a mobile hotspot depends on how good your mobile data signal is, and how much it costs you. If you want to activate the mobile hotspot on your phone, you usually either have to pay an additional fee to your wireless carrier (Verizon and AT&T) or get it free but have a cap on your tethering/month (T-Mobile). If you don't have unlimited data, using your phone as a hotspot for a computer can really eat up data fast, because most people use their computers for more intensive data usage (like streaming high quality movies or music).