Fitness routines and How to balance work, life and fitness?

Hi, Im trying to figure out a healthy gym routine that fits my life. Im 20F, 5'9", around 210lbs, and want to get back to 170lbs, but im not sure where to start or how to squeeze the gym into my schedule. I work as a diesel technician Sunday 9 am to 6 pm and Monday to Thursday 6 am to 2:30 pm, and it's an hour drive each way. So, after work seems like the best time for me. Should i go every day or have set days? What kind of workouts should i do? How long should i be at the gym when i go? Ive tried calorie counting and supplements a family member suggested, plus going to the gym, but consistency is a struggle. I lost 30 pounds when i was consistent but gained 10 back, and ive never really had a good gym routine or schedule, so i need advice on how to stay consistent.