A lot of people wrestle with procrastination. You're right, you're not stupid, you need to get organized. You might find the following tips useful:

a) break your work down into manageable tasks

for example: if you have to clean your room, you might decide to start with your desk, then move onto the floor, etc. (do one job at a time) You don't have to do all the work at once. Take breaks - it doesn't have to be done in one day!

Make a plan. Getting started is the trickies part but once you have begun, you may find that the job isn't as overwhelming as you initially thought it was.

b) make the job fun or interesting

for example: play some great music you enjoy listening to. Be creative. If you're cleaning your room, take some time to re-arrange your stuff and experiment - move your desk to another corner.

c) reward yourself.

Give yourself a break for completing a specific task. Treat yourself to something you might find relaxing and enjoying. Indulge yourself.

Tricky question. It sounds as though because you just fought, everyone is upset. Why not give your parents (and yourself) some time to cool off. When everyone has calmed down, you could try to approach them with some conditions:

If you got a job, you would:

a) maintain your grades (be specific)

b) if they don't want you to work evenings, what about during the weekends?

c) limit your work hours.

Is there anyway you could make some extra money around the house? For example, could your parents "hire" you to clean out the garage or wash the car?

Remember to keep in mind that your parents will be more responsive if you approach them calmly and with a well-thought out plan.

Good luck!