You have mentioned that you have lots of roost space. What is lots to you? In general I think you need about 1 linear foot of roost per bird. My advice is to get rid of that rooster and get back down to the 6 that the coup can house. It's tough I know, but quality(of life and your enjoyment of the chickens) over quantity. 6 chickens is not a bad number of birds. Can your family eat 3+ dozen eggs a week? If not then any more than 6 chickens is indulgence and not necessity. If you are short on money then necessity should come first. All is not lost though, in due time things will change and you will be able to go bigger, but in the right way and not in a hurried unplanned way. You're only 15, don't be in a hurry. Things done in a unplanned, chaotic way usually don't last long. Make out your plan, save for it, gather any free materials you can find and I bet by next year you could make it all happen and in a much better way that if you hurry along and hope for the best.