Healthy eating

I need help, I have recently gained a bit of weight and would like to lose around 20 lbs. I’ve started running multiple times per week but I can’t nail the eating healthy thing, it’s hard for me because I’m young and live with my parents who work erratic schedules and the majority of my family is extremely picky. Due to these things we often don’t cook a real balanced meal and we have A LOT of junk food in my house. I’ve seen my mom gain and lose weight over the years and currently I believe she is classified as obese. I don’t want to end up like my mom so I need help. How do I resist the temptation and curb the cravings for all this junk food?