Do not give up on your trying to make your parents understand that you feel there is a reason for your difficulties. You could try writing or typing a list of things you have trouble with, along with any basic information about dyspraxia relevant to your difficulties. Copy and paste anything from this site if it helps. Visit the Dyspraxia Foundation site too, for more info at <a href='http://www.dyspraxiafoundation.org.uk/' target='_blank'>Dyspraxia Foundation</a>. List the addresses of the sites you get your information from. Then try another chat with your mum and Dad. Show them your list and encourage them to have a look at the websites with you. Stay calm and try not to loose your temper. It may take a while, but just keep trying. Ask your Mum if she will make an appointment for you to see the doctor, so you can arrange for an assessment.
But if this fails and you feel your parents are still not listening, then you could try some of the following:
I do not know how old you are, but is there any way you could make an appointment to see your family doctor on your own. If you can, then explain to your doctor your worries and the things that you have difficulty with. Tell him/her that you have tried to discuss your concerns with your parents, but they do not realise how much of a problem you are having. Ask your Dr if there is any way that you can have an assessment to find out the cause of your difficulty. You could even show your list if you made one.
Are there any teachers at school who you trust who you could talk to? If there are then speak to them. Tell them you have concerns with your maths, writing etc. and would very much like some help in improving those things. Could you have a chat with your PE teacher about your co-ordination skills? Have the teachers ever noticed that you struugle with certain things and if so have they discussed it with your parents? If not ask your teacher if they feel you are struggling and if so could they have a chat with your parents or help you find ways to cope. I know it is going to take real courage on your part, but you need to find some one who will listen to you and help you.
Hope that some of this helps.
Let us know how you get on.
All the very best,