Help losing weight and gaining muscle

Depends a lot on how you do it and as the previous response:

1 - eating at a deficit will lose both
2 - lifting can build muscle if you make sure you get enough protien, but it can also help you lose because muscles burn energy, and
3 - if, when you lift, you get and keep your hear rate up by not pausing more than 30-40 seconds between sets and exercises.

Or at least it has worked for me!

At 18 years of age, at 6'1 and 175, you shouldn't need to lose much fat. But read what the earlier posters have said. For most people, and you included, losing weight and gaining muscle are mutually exclusive propositions. It can't be done. Different body processes (anabolic versus catabolic). Focus on one at a time -- gaining muscle or losing fat. When you lose fat, you will lose lean body mass. Lifting will minimize that loss considerably, but not entirely. When you gain muscle you will naturally gain a bit of fat. Just the way it works. There are no magic steps to do both simultaneously.

And 1500 calories is way to low to add muscle. You need to be at a surplus to your TDEE to add muscle, not deficit. Using a quick calculation over at Scooby's Workshop from what you said, your BMR is about 1867 calories/day. Your TDEE is about 2897. To gain weight and muscle you would need to be at about 3147 calories. or more than twice what you said. That is to gain muscle.

To lose weight, the BMR and TDEE stays the same, but you'd need to be at about 2752 assuming you are using TDEE - 5%. And you shouldn't be going too high because you can't have too much fat to lose. Not at 6'1, 175 and age 18.

Sorry, but it is a constant balancing act. Which is why bodybuilders will bulk up during off-season, adding muscle and fat. Then cut during competition season. If you could do both, don't you think the bodybuilders, who are better at this than anyone, would know how to do both simultaneously. The fact they don't should tell you something.

And keep lifting no matter what you do.