Seeing the Sadducees had been silenced on their question about death and resurrection, the Pharisees sent a lawyer to test Jesus concerning what was 'the great commandment' (Matthew 22.35, AV). Jesus replied by quoting the Shema (Deut 6.4). Love the Lord your God from the heart, the inner core of your being.To this commandment, Jesus added a commandment that is 'like the first': 'love your neighbour as yourself'. In the latter, Jesus was quoting Leviticus 19.18 which, one source translated as 'You are not to take-vengeance, you are not to retain-anger against the sons of your kinspeople—but be-loving to your neighbor (as one) like yourself, I am YHWH [the LORD]!'
The gloss in brackets (so), which I have seen elsewhere, puts a different complexion on usual interpretations of the verse because it takes away our selfish fixation about self-love. I doubt the verse has anything to do with loving ourselves as such although it is sometimes 'exegeted' as if without proper self-love we cannot love others. In any case, the be-loving to your neighbour is set within the context of not taking vengeance, not retaining-anger against one's kinsfolk which, makes that interpretation foreign to the setting.
Jesus' view of neighbour was broader than that of Jewry and the love commended is action that wishes good towards any we come in contact with. It has little to do with sentiment or even liking the neighbour; biblical love is wanting the best for the neighbour and doing good to the neighbour as the Good Samaritan did.
Herman Dooyeweerd the great Dutch jurist and philosopher said that these two commandments are a supratemporal unity that is differentiated or particularised throughout the temporal world. So, we face the call to be-loving of God and neighbour at every turn in temporal existence. This ubiquitous law is not displaced by love because the undifferentiated meaning of law is love. To love Christ is to keep his commandments (Jn 14.15, 23) and the commandment is to love another (Jn 15.12-13) as we have been loved.
