“I find myself hesitating when I speak because I am second-guessing myself and correcting myself.”
You are most likely someone who uses their “monitor” too much.
The Monitor Hypothesis is the idea that many people who try to learn a second language as an adult have constructed a sort of mental computer monitor between their thought in their mother tongue and their speech. This monitor is where they try out their grammar and construction before they actually say it. They sort of put their sentence or phrase up on the monitor screen to check it over before they talk or even while they are talking. The assumption behind the hypothesis is that this monitor is a hinderence to fluency and is of little to no benefit for accuracy in the long run.
So what is the problem really? Some would say that the problem is that your whole approach to learning the language so far is at fault. You have been trying to learn language as a system of rules and tranformations and translating methods instead of acquiring it. Acquisition is supposedly the natural way that a child learns the language without conscious analysis of the rules (i.e left brain). Therefore, we should be as childlike as possible when we try to learn/acquire a language.
Others would say that an adult has advantages over a child when learning a language because he or she can learn shortcuts and rules and can analyze the language and learn from mistakes. We can use both sides of our brain. (Have you ever tried to correct a child’s grammar? “Jimmy, we don’t say ‘goed’ we say ‘went.’ I know Mommy. I goed and went with Tommy to the store.”) We are great suckers for anything that is touted as “natural.”
I think both sides have a point. Most people who have an active monitor are producing just as many mistakes as those with no monitor. However, given time to think about it, the active monitor user can sometimes produce more grammatical sentences. However, if you find that your fluency is suffering because of this kind of hesitation and you are already an adult in a language program, you do not have a hopeless condition. There are still some exercises you can do to improve your fluency.
1) Practice speaking quickly and incorrectly. You don’t need to be constantly wondering if this is the correct way to say something. For most situations it is perfectly fine to make mistakes as you speak and most of your mistakes should disappear as you are exposed to more and more native speech.
2) Try recording yourself for short talks. When you know your speech is recorded, you know you can listen to it later to analyze and correct your mistakes. It brings a kind of freedom from the tyranny of the monitor.
3) Time yourself talking. How long can you go without hesitating or correcting yourself? If you have in front of you a picture story or written notes about what you want to talk about, you can practice talking about that topic going faster and faster each time. If you get stuck on a vocabulary word or a structure, just say it in your language and go on. Don’t get sloppy with your pronunciation, but you can be sloppy with your grammar.
4) Familiar dialogues (for example, dialogues from your book) are good for fluency practice as well. You don’t have to wonder about what to say, just how fluently you can say it.