There are a number of places in Genesis where the “angel of the LORD” seems to be used for God Himself.
For instance, when Abraham was about to sacrifice Isaac:
10] Then Abraham put forth his hand, and took the knife to slay his son.
11] But the angel of the LORD called to him from heaven, and said, “Abraham, Abraham!” And he said, “Here am I.”
12] He said, “Do not lay your hand on the lad or do anything to him; for now I know that you fear God, seeing you have not withheld your son, your only son, from me.”
The “angel” seems to refer to himself as God.
Also, the “man” that talked to Abraham, who was first in the company of the two that went down to Lot in Sodom, was God Himself. And the “man” that Jacob wrestled with was God. It might be that these “incarnations” were the Second Person of the Trinity. As noted above, the notion is not heretical.
Also, in a sense, Jesus was a messenger of God, so he is an angelos=messenger. But our Lord is definitely not a member of that class of spiritual beings referred to specifically as angels. That would be heretical.