You refer to the book The Great Controversy. Here is a sentence from pp. 446, 447.
It was in behalf of the Sunday that popery first asserted its arrogant claims (see Appendix); and its first resort to the power of the state was to compel the observance of Sunday as “the Lord’s day.”
The first half of this sentence refers to Bishop Victor I attempting to excommunicate the church of the East because all those Christians refused to remember Christ's resurrection on Easter Sunday. The date of that attempt would be around 190 AD. And thus the very source you referred to does acknowledge that there were efforts by the bishop of Rome to force Sunday on others by around 190 AD.
An early step in the replacement of the Bible Sabbath with Sunday was the honoring of Easter Sunday. The eastern practice of remembering the resurrection on Nisan 14 was at variance with this.
Note that Justin Martyr was opposed to the idea of resting from work on Sunday. So even if his Sunday worship passage wasn't a forgery, it doesn't help much to advance the idea that Sunday had already replaced the Sabbath by his time as the way to fulfill the 4th commandment. That did not happen, it seems to me, until the 6th century.
So the best that the passage from Justin, if authentic, can be used for is to show that some professed Christians in his day had gotten to the point where they no longer believed the Pauline concepts that (a) by the law is the knowledge of sin, and (b) the believer should not "continue in sin."
And yet Justin's writings on the Sabbath issue can also be used to show that significant numbers of Christians in his day were still keeping the Bible Sabbath. If that had not been the case, he would never have said he didn't like Sabbath-keeping Christians telling him that he needed to keep the Sabbath.