I agree... you can get through this. It sounds to me (and I could be wrong and please correct me if I am) like you are suffering from a lot of anxiety, stress, and overload, among other things.
Sometimes when that is the case, especially considering what other emotional and physical struggles might be an issue on a regular basis, it can have a huge effect on your ability to think clearly, function, and feel confident or in control.
More often people feel confused, feel ike something is wrong, they feel forgetful (because during stressful times we are usually doing many things at once, taking in huge amounts of info at a time, and our nervous system is working overtime), then there are often feelings of frustration or irritability, people can become angry with themselves, become depressed, make mistakes they normally wouldn't, and so on and on....
I really think if this is even part of what is going on in your life you should really take care of yourself, find some time to do some relaxing things just for yourself, and please try not to beat yourself up. You are going to make it through the tough times.
Of course we are always here for you so you aren't alone while you try to navigate through those tough times.
