ABS/Brake/Check Engine lights & Speedometer

So just over a week ago, my ABS and Brake lights came on, and my speedometer stopped working. Sometimes my car will be like this, and other times it'll be just fine. After doing some research, my family and I concluded that it's most likely that the ABS module needs to be replaced. For extra measure, I had the cable connected to the module up underneath my radiator checked for corrosion, and it was fine. Fast forward to today. My primary concern has been driving in rain without the ABS - which I don't know how to do. So imagine my surprise when the ABS and Brake lights were off, but the Check Engine light is now on! And just my luck, I'm almost home when the ABS and Brake lights come back on and my speedometer stops working again. So, now my ABS, Brake, and Check Engine lights are on, and my speedometer isn't working. Do you maybe have an idea of what might be wrong with my car?