I need major weight loss advice/tips...

I’m a senior in high school, 5’6, and approaching 300lbs. Not there yet, but with the path I’m on, I’ll see that number on the weight scale soon. I’ve always struggled with my weight and I try to love myself for how I am, but if I’m being honest..I feel disgusting every minute I’m awake. I’m always thinking about how I wish I was skinnier or how I would even start that process and when I’m not thinking about that, I’m subconsciously trying to make myself not seem so, big. I pull at my shirt to hide my rolls, I try to suck in my stomach a little more, say no to anyone that offers me food even though I’ve been looking at their plate for ten minutes. I want to look nice for prom and feel pretty when I walk across the stage at graduation. I want to actually be confident and feel like I’m beautiful. This is a disgusting habit and I want out. I’ve been doing small exercises (barely started) but I feel so rushed to want to see more change or that I’m not doing enough to see that change faster. If anyone can comment down below some exercise routines or diet tips that has helped them lose major weight fast, please do so. I’m scared of where I’m going physically and mentally. I just want to be healthy and happy. Please help.