Yes, stress is one likely cause for your feeling tired. Sometimes, we do not even know we are stressed if we are not attentive to little signals our body try to hint us.
Firstly, understand that medication is just a temporary solution. So try to avoid it as much as possible. Else it will usually create another problem, addiction to the medication.
Some of the other causes of our feeling tired is the diet we in. For example, if you take cold drink, or fruits, for some people it can cause you to feel tired. You can try to totally avoid these things for a week and see if you situation improve.
Beside your problem of feeling tired, you mentioned that your life is also stressful because of 2 autism kids and have not one to turn to. If you are interested to see a major change in your life for the better, do not take the easy way out, go for the root of the problem.
To do that you have to know that today we are all living in a dream thinking they are real. Not convinced? Try this experiment; go watch your favourite tv program and make sure you do not have any disturbance during this time. At this time, is your life totally wonderful? No more fear, stress, unhappiness. You are only feeling the same way as the tv program.
So during this time, what happened to all your fear, stress, unhappiness? The answer is simple, all our fear, stress and unhappiness is created by our thinking. Once you cease to think about it, it no longer have power over you. In fact the kind of life we think we have are all a delusion, they are all created by our thinking. You think that your life is miserable because you have 2 autism kids, that is a delusion. You think that life is not fair because there is no one there to help you and for you to turn to? That is also a delusion. They are all a delusion because if you do not think about it, they no longer exist anymore.
"But these situation is a fact and I do have 2 autism kids whether I think about them or not." you may say. In fact that is what most people think. But the fact is this...
If you do not think about it, you will not see your kids as autism kids, you see them as just kids.
If you do not think about it, then when they again and again shouted, make a mess of things, you would not mind. Because now that you do not think about it, each time is just like the first time they are doing it. And to you their shout is no longer a problem when you do not think about it, the mess is no longer a problem when you do not think about it. A shout is just a shout, neither good nor bad when you do not think about it.
If you do not think about it, each time you clean up their mess, you do not think about the misery of you cleaning up their mess again and again, for each time, you just do it. You do not think if what you are doing is good or bad, you just do it.
Hope I am not too confusing to you
, but hope you can see that everything is just an illusion. So do not think your problem is too huge to be solved or removed. Because they are an illusion, when you know are no longer living in your current dream, all your problems will evaporate into thin air.
So how do we solve the problem. For a start, go purchase the audio CD on "The Power Of Now" by Eckhart Tolle. It will totally straighten out your view of the world. This is one of the best work I have seen in the commercial market. At the meantime, do the following yoga breathing exercises as often as you can;
Take in 3 counts of deep breath to your lower abdominal (2 fingers below navel) and 7 counts of slow breathing out. During these breathing, relax your whole body and your mind and just bring your attention to your lower abdominal. When you have thinking, do not worry about it and do not analyze it. Just bring you mind back to your lower abdominal.
If you want more clarification or details, you can continue to post through this thread .
All the best!