You have two choices: You hire an accountant, or you do it yourself. Your accountant is getting £170 a month for very little work. The government websites are quite decent, so you can do this yourself. As a software developer, I don't expect you to have too many different expenses (one big chunk for using your car or paying for public transport, and that's mostly it. If you miss out on £100 of things that you could have expensed, that costs you £20 compared to £170 for the accountant). And the work is proportional to the number of expenses, not the amount.
By the way, to HMRC your company is trading. You just submit your income / expenses every 3 months. Importantly you will employ yourself all the time nobody else employes you, and you need to handle that right. Again, government website is quite helpful.
There's no point telling HMRC you are not trading. You have to tell them at regular intervals what was the company's income and what was the expenses. You can tell them "the company's income was zero, the expenses were zero". If that's what happens, that's all you need to do.
In practice, your company should be employing you at a very low wage, meaning the company should pay you something like £800 a month as salary, and zero or close to zero income tax and employee NI. So your company has expenses which will reduce your annual profit and your company taxes.