I have a 2016 Hyundai Elantra. It recently doesn't want to start?

Hello. Over the winter my car started this thing of not always wanting to start, or I should remain started. It's definitely worse in cold weather. Trying the key again can result in it either not starting or again not staying started. Giving it gas sometimes helps. It's not every time just sometimes but often enough to concern me. It turns over and starts but the rpms lower and it dies shortly after. My boyfriend has mentioned maybe the starter, or fuel injector. I could really use any kind of ideas to go off of. I'm a mom that works 40-50 hours a week and it is my only means of transportation to and from work and to pick up my littles.