Living at home

Are they open to helping you? You could figure out what you'd like to be eating for breakfasts, lunches, and snacks, and give them a list so they could pick you up some things when they grocery shop. Or you could go along with and pick some things out. They might also be open to making different meals or making different components (say, adding an easy veggie dish) or preparing food a bit differently. Or they might allow you to do this if you were willing to do the cooking / help with the cooking.

If they are not open to helping you, you could get creative. Say you'd like to learn to cook before you move away, and that you'd like to take over doing dinners. Or volunteer to go during the grocery shops and see if you can get food you want ("oh hey that would make a good snack to take to school" or "oh this looks good, can we try this yoghurt instead of our usual?" type thing).

Otherwise... see if you can eat around them a bit. Scoop more of the veggies and less of something else, then get fruit from the fridge later. (I don't know what they eat or how they stock their kitchen, so I don't know if this will apply.)

Also, what's your weekly lb loss set to? When you don't have complete control over food (I don't either), it can be easier to set the goal to the most modest (which I think is 0.5 lb/wk but you could try 1 lb). This way it is easier to meet your goal, and you will feel better and less frustrated. And try to work on accepting it to an extent -- imperfection is okay. Do your best. You will make progress, and even if it isn't all exactly how you wanted, it will still be great.

Finally: Are you exercising? If not, you could check out Blogilates. Cassey Ho is super positive and fun to work out with, there are new things to do every day, and it only requires a yoga mat (or towel). It's also free!