Trouble speaking and stumbling on words?

For over half a year i have struggled with speaking. Every sentence i usually stumble on a few words and my sentences dont seem to flow. Im pretty sure i found the cause to my problem and that is thinking about the movements of my mouth the entire time while speaking. Knowing that i wasnt talking perfectly i would try to move my tongue and lips in different ways to try to produce a different sound that i heard in the past hoping that it would perfect but it ends up being worse. This all started happening when i started smoking marijuana in 9th grade and i smoked almost every other day. When im high my speech is exceptionally bad. Im not sure if weed has caused this problem or that weed has caused me to overthink and now im thinking about how my mouth moves when i talk. Nobody that i have talked to has really seemed to notice but i do and it makes me very angry. How can i start talking perfectly again?