The first thing you need to do is speak to an expert in planning drawings. Find a local expert who can go through the extension plan with you. They can look at your idea, work out where you are not meeting regulations, and set up a meeting to try and overcome these issues.
This is the best advice that I can give you. Extensions are hard to get right, but you cannot simply ignore regulations. Therefore, you should look to work with a specialist in planning. They can determine where you might have made mistakes and work with the planning authority to find a solution.
If nothing else, they can begin drawing up plans from scratch with you. You should not try and ignore or skirt around building regulations; they are there for a reason, so ensure your plans match up.