Braveheart... Respectfully.... I know you're new to the forum but I've been around for many years and have replied to pages of this fear. Not one person in all that time had ALS or MND. Not. One! You "think" you have slurred speech. Slurred speech due to ALS is caused by your tongue not working and actually failing. It wouldn't be sporadic or here and there. It would be all the time. People would notice. The same would be if it were any other part of your body. The muscle stops working. Think it as your Wifi going out. No matter how many times you try to navigate the web, nothing happens.
You have a friend who was recently diagnosed (sorry to hear about that) and that is the trigger to your anxiety spiral. You've engaged in classic HA behavior, self testing, consulted Dr. Google and most of all, you're posting on an anxiety website looking for reassurance. That link is all the reassurance you need. It's up to you to accept it and look at treating the real issue here.
Positive thoughts