No, it's so hard to understand that even Paul "misunderstood" it. The apostle did not "understand" that the Law would last forever and that he was supposed to teach Gentiles to keep all of the Torah.
Well I think it is easy to understand.
Are all prophecies about Jesus fulfilled?
My answer is no, He still has the 2nd coming.
Has heaven and earth passsed away?
Matthew 5:18-20, " 18 For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished. 19 Therefore whoever relaxes one of the least of these commandments and teaches others to do the same will be called least in the kingdom of heaven, but whoever does them and teaches them will be called great in the kingdom of heaven. 20 For I tell you, unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven.
No that is still future, it is spoken of in the book of Revelation;
Revelation 21:1-2, " 1 Then I saw a new heaven and a new earth,
for the first heaven and the first earth had passed away, and the sea was no more. 2 And I saw the holy city, new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband."
Also even if you do think heaven and earth has already passed, there is this:
Matthew 24:35, "Heaven and earth will pass away, but my words will not pass away. "
I think it is very simple. Also pray on it, the holy Spirit guides us to all truth.