It sounds like you’re not getting enough breath which is causing you to run out quicker and speak a bit low. You want a lot of breath so that you naturally project, while also projecting as much as you can to fit the scenario of the gym. You don’t want to sound as if you’re reading a script, so try to bring some dynamic changes to your performance to enhance it and make the audience really dialed in on what you’re saying to them. Work on your breathing exercises and straw exercise to increase your lung capacity for air which will greatly improve your projection, articulation and pretty much everything! Good job and keep it up!