My two cents: take the internship, hustle your way to pay off rent (you mentioned Lyft), and cut back on any extra activities ie dinners out, concerts, etc. You will learn a lot about yourself during this experience. I know I did when I was making less than $30k and going/paying for grad school at NYU.
Most importantly during the internship, which you will not get at the gym job, *network* with as many people in the tech company (and community) as possible. And after you meet anyone, from the receptionist to the CEO, connect on LI immediately.
Not only do you need to build valuable experience but you need to build and cultivate your personal network.