Hi Jennifer: You would not be breaking needles if you just had the machine threaded wrong, it just wouldn't sew properly. Are you using the correct needles for your machine? Your needle system is 135X17. If you are using the correct needle installed correctly with the grooved side to the left and the scarf of the needle to the right and it is pushed all the way up into the needle bar then you need to take it in for service. You don't have a piece of broken needle shank up in the needle bar so the needle can't go all the way up do you? It sounds more like the machine is out of time to me.
No one lives forever, the trick is creating something that will.