In a previous thread a few weeks before I told you how you can at least change some water without your parents helping. Take a bucket or even juice jug (make sure they are clean) and just start removing water and dumping it in the toilet until you have taken AT LEAST 50% of the water out. Then clean and refill the container adding dechlorinator and start refilling... it may take a lot longer this way but you owe it to your fish... either that or just rehome them all. True, this is not a good cleaning as you aren't doing the gravel, but its better than no cleaning at all.
If you aren't cleaning the gravel you HAVE TO change the water more often, every 2-3 days I'd think if you want to maintain healthy fish.