Answer: You are right when you say that Egyptian hieroglyphs might very well have been the first form of writing. Here is part of a BBC news article:
The earliest writing ever seen may have been discovered in southern Egypt. The hieroglyphics record linen and oil deliveries made over 5,000 years ago. The find challenges the widely-held belief that the first people to write were the Sumerians of Mesopotamia (modern-day Iraq) sometime before 3000 BC. The exact date of Sumerian writing remains in doubt but the new Egyptian discoveries have been confidently dated to between 3300 BC and 3200 BC using carbon isotopes.
I can't quote any more of the article as I would be breaking copyright but you can find the original article by typing "Were the Egyptians the first scribes?" into the google internet browser. The article suggests that the Sumerians may have traded with ancient Egypt and copied the hieroglyphic script that way. Sorry I don't know where the script used to write English words came from. There are similarities in Latin and Greek, but I don't know where their scripts came from. You would have to see if Latin and Greek scripts are similar to Sumerian and connect hieroglyphs that way.

How hieroglyphs died out is much more certain. Hieroglyph comes from two Greek words. When the Greeks invaded ancient Egypt they found that hieroglyphs were used mostly in religious writings and on the walls of temples and monuments, so they called them Hieros (sacred) grapho (writing). Thus the word hieroglyphs has come down to us. BTW in English "hieroglyphs" is a noun - that is it is the name of the script by which the ancient Egyptian language is written. "Hieroglyphic" is an adjective describing the script. So Egyptian scribes wrote in "hieroglyphs" and the inscriptions carved on tomb walls are "hieroglyphic inscriptions"The ancient Egyptians spoke the ancient Egyptian language and wrote it in hieroglyphs and the more cursive form the dempotic script. Demotic was used to record everyday affairs, both personal and business. Hieroglyphs were used for religious and important state matters. Mostly only used by professional scribes, priests and a few highly educated individuals. That is why the Rosetta stone was written in three scripts - Hieroglyphs, Demotic and Greek - so that everyone could read it. Greek because Egypt was ruled by the Greek Ptolemies at that time. You can find lots of good information about the Rosetta Stone on the web.Ê The latest hieroglyphic script found dates from 396AD on the walls of a temple on the island of Philae. The reason hieroglyphs went out of use was that by that time the Romans were occupying Egypt and the Emporer Theodocius made Christianity the state religion and outlawed the worship of the Egyptian gods. As the meaning of the name implies, (sacred writing) Egyptian hieroglyphs were usually found in tombs, temples and on monuments. So with the outlawing of the worship of the Egyptian gods, hieroglyphs, being "sacred words" dropped out of use because of this. You can see how involved this subject is.
Your statement "I have been to Egypt many times ..." caught my interest. It is not a statement one hears often. I have too and love everything about Egypt; ancient and modern. If you have the time, I would like to hear about how and why you have been to Egypt many times. Regards and best wishes for the new year.