If Astarte would have responded, the first thing she would have ensured is that you would have divorced each other as she knows even better than us humans that race mixing is a mortal sin that must be avoided whatever the means, no matter the cost.
Now, this is off-topic, but I will ask the following. Maybe it is me, but somehow I have noticed that recently there are so many retarded questions about race mixing. Is it only me or other people here who also notice this trend that people started asking way too much about race mixing?
HP had wrote before that the Gods are not going to let society collapse in order for certain changes to happen, even if we think they would be positive. I believe the same is true here, where the Gods are not going to simply and immediately tear apart the relationship by their hand, because this won't lead to a positive outcome.
Rather, I believe the OP actually did receive a sign, by she is avoiding it. She said she saw an increase in content or thoughts pertaining to race-mixing being bad, therefore it sounds like the Gods are trying to put her back on a path of healing, which she will learn and do by her own will, and through a slower and more realistic development.
As Epiphany and others pointed out, it sounds like an unfortunate case where the person's urges or desires took over and she herself manifested this partner and situation, not the Gods.
This is certainly a sad situation, but it is not the end of the world. To the OP, despite the coincidence or other positive feelings you may have ascribed to your boyfriend, know that you can find the same and more in another boyfriend of your race. It will be hard to correct this mistake, but it is possible and should be done. Avoiding it will only make the situation worse for both you and your partner.
The sooner the break-up occurs, the easier it will be to move on. That also doesn't mean you cannot be happy or thankful about certain benefits this man gave you, including friendship or emotional support, nor does it mean any breakup cannot be done in a mutual and positive fashion, but the relationship in its current state cannot exist any longer. Both you and this man need to find proper partners, not remain in a situation that will cause immense pain if this is extrapolated for years into the future.