May you have peace!
You ask:
If I choose not to love God or my neighbor, is that wrong, unethical.
The problem is that, like many others, you are in fear of the potential "punishment," which fear causes you to miss the important point that my Lord was teaching. It is not about what will happen if you DON'T love God or your neighbor; it is about what will happen if you DO:
"He that has my commandments and observes them, that one is he who loves me. In turn, he that loves me will be loved by my Father, and I will love him... and will plainly show myself to him.... If anyone loves me, he will observe my word, and my Father will love him, and we shall come to him and make our abode with him." John 14:21, 23
Here's were we go wrong: we been taught to... and so live... in FEAR... rather than in LOVE. But LOVE... casts ALL fear... OUTSIDE. We have spent SO much of our lives overshadowing love... with fear. What we must learn is to conquer FEAR... and thus, HATE... with love.
It is not easy to do. Being fearful is SO much easier because it's what we've been taught all our lives. Why? Because we are physical beings living in a physical world... a world in which there are at least two things the physical body fears: pain (of all types)... and death.
But the Most Holy One of Israel has given us One who has conquered all three: fear, pain and death! And that One promises that if you obey his commandments, you, too, can conquer fear of pain and death... now... and, in the future, death.
How can you do it now? By allowing him to come... and reside IN you... he and the Father. In this way, you will be guided... and comforted. How later? By dwelling in you, THEY will "make your mortal alive..." when the time to do so arrives. Knowing this, you learn to fear nothing, including pain and death.
And you allow this dwelling... this residence in you... by obeying his commandments. Which are the two you mentioned, and a couple/few more.
I hope this helps and I bid you peace.
Your servant and a slave of Christ,
SA