Mr. jewel
First of all the translation you are giving is WRONG. The ayat under discussion does not say anywhere the word "ALL".
Secondly, this ayat is talking in general of the prophets that Mohammed SAW is just a Prophet like the prophets passed before him.
Thirdly, the ayats i have mentioned are in particular about Hazrat Eisa Alihissalam.
Fourth, as brother Ibrar mentioned Quran is always understood according to the sunnah, as we have lots of authentic ahadiths saying Hazrat Eisa Alaihissalam is alive so it guides us about the meaning of the ayat you are considering, i.e. it is not all prophets and it is in general for the prophets passed before Prophet SAW. And the aim of this ayat was that Allah SWT wanted to guide its servants at the critical time of the Prophets death, that if Prophet SAW will die or is killed, will you go on your heels and loose your faith. Subhan'Allah and like wise Hazrat Abu Bakr RAA said at that time that those who worshipped Mohammed (SAW) they should know that he (SAW) is dead, and those who worship Allah SWT they should know that HE will never die. Subhan'Allah.
Now i hope the topic is clear, other wise you can believe in anything you want. It is up to Allah SWT, He guides whom ever he wish.
Wa ma alaina illal balagh.