When i talk i can't pronounce some word few timesi overthink and i can't talk normal, my tongue get rattled and i can't pronounce things no longer.why?

Go to doctor: If you have slurred or unusual speech alert your parents immediately and seek medical evaluation.

Altered speech: Please seek immediate evaluation. Sudden onset altered speech is a sign of stroke. If this is a problem that has come on gradually, there may be a neurologic component. There are also other possibilities. So don't wait, see Physician, Urgent Care, or ER now.