Your problem is a common one- and no it doesn't sound stupid.

It sounds like you're nice& want a good future. But the teenage years are hard on everyone; your hormones are racing and you can't focus on things for long periods of time. It all feels like too much effort. So you 'muck around' as you put it, then you feel worried& regret it.

I think what would work is making a schedule for yourself- and trying to stick to it.

Studying should not be the only thing in your life. There should be time for fun, time for hobbies, time for friends, and time for studies.

When you're in school, try to focus. When you feel you're going to space out, count to ten and make that effort. Whatever you do, make it a point to be polite to your teachers. That way, when you don't always do well in exams they will be more inclined to help out.

It's important that you eat well and get a good night's sleep (at least 8 hours) so that you can focus and function well during the day.

A brisk walk or some exercise (swimming or basket ball) anything you like will help work off excess energy in a good way. Plus you'll be fit and healthy.

Avoid fatty and fried foods. Avoid too much candy or sugary drinks. Cut out sodas and drink lots of water.

Try talking to people your age who are doing well at school, so you can do what they're doing. If your friends don't care about doing well in school, make friends who DO care. Study time with friends is also good and will help you focus more.

It's also a good idea to talk to your parents or a teacher- any understanding grow up- or a school counsellor who will keep things confidential. Tell this adult honestly how you feel. Getting your feelings off your chest will help.

If you need a teacher or counselor to help you make a study schedule, they can also do that.

If you get tired a lot, your parents should take you to the doctor. Or you can go alone- just to make sure there's no physical reason for your tiredness.

But letting out your feelings to someone you can trust, studying with friends who care about making good grades, setting a study schedule and sticking to it, eating and sleeping well, exercising, being polite to your teachers, and making the effort to focus: All these things will help you.

Remember that this is just a hard phase and it will pass. And you can always make up a bad grade on a an exam by studying harder and more.

All this will pass.