I constantly focus on every word when speaking – how can I stop this?

I constantly focus on every word when speaking – how can I stop this? Hi everyone I've been struggling with speech problems for 2–3 years. I'm 20 years old and I don’t exactly know what caused it. When I speak, I’m always focusing on every single word. When I concentrate, I usually say the word, but I often replace it with an easier one, say it quietly, or pause for a moment. It’s not a full block, more like constant control over my speech. Some sounds (P, K, T, O) are especially difficult for me. I feel anxiety and fear mainly in front of groups of people or when I have to introduce myself – my heart beats very fast in those situations. When I’m just concentrating on words and speaking normally, my heart doesn’t race, but I’m extremely focused on what I say. Spontaneous or quick things, like when someone asks me my name or birthday quickly, cause a mild speech block. I avoid parties and strangers, I don’t call anyone, and I don’t handle things in stores. I’d like to ask: How can I stop focusing on every single word? How can I stop thinking about speech blocks and stuttering while speaking? Who should I see, and how long does treatment usually take? What is a fast but effective solution?