Hi! Welcome to our forum.
It sounds to me like you have anxiety and trust me when I say that all of us here understand what you're going through and we don't like it much either! But the good news is that there is help for this condition.
When you say you get nervous "at just a single thought," are they a specific kind of thought? Are they scary, negative or worrisome?
The one thing you wrote that has me the most concerned is "I hate going anywhere because it makes me sick/nervous." That is not just anxiety, that is what is known as agoraphobia and if not treated can leave you totally housebound.
I suggest a visit to your doctor to rule out any underlying cause for this anxiety and then getting into some therapy to help you learn to cope with this. You may be put on meds, but they are nothing to be frightened of and combined with therapy, you will soon feel like yourself again.There is nothing "wrong" with you............there are millions of us out here with anxiety disorders living perfectly normal lives,
Please get the help you need and let us know how you're doing, OK?
Peace
Greenlydia