Sexual

This is normal. 

Dealing with one's urges when they are inconvenient is also part of the human condition. Unfortunately there is currently no solution to one of the problems of modernity: that biological maturity (puberty) happens before social maturity (at which time one usually marries).

Islamically, the shariah-prescribed options are marriage (regardless of whether it involves traditional social roles or not, what form it takes, etc) or abstinence. 

Marriage: That's between yourself and your family and your personal/social situation. There are other questions here that discuss that which you could look at.

Abstinence: Forewarned is forearmed. Since you know what days will be more challenging, you can explore what sort of interventions help calm your hormones down. Some women find it helpful to exercise more or avoid certain foods around those days (especially chocolate, meat, or animal products - especially given how many hormones are given to animals today). One can also simply try to think about other things.

Fasting doesn't usually seem to have the same effect on women that it seems to on men with respect to calming down one's urgers (in fact many women say it has the opposite effect), but everyone is different.

Ideally, the higher side of the human being should control the animal side, in a way that a horseman controls his steed. In reality, this is often a work in progress for people. But, there is a virtue in trying.

I understand this is a sensitive subject and one that one should treat carefully.

While I can understand why this could come across as inexcusable in this day and age, to my understanding, in the past in that region, there were not very opportunities for earning an income or survival on your own without a family or tribe, and slaves were particularly vulnerable. So a slave-girl would be integrated into the man's household as part of the household (so in essence, part of the structure) in which he was responsible for her, and that was often strengthened through relations. That is, for men of means, the family household was often larger than just a wife and children. Conversely, it seems that at some point in early Islamic history, it became common for some men to essentially take a slave woman as a wife, rather than marry a free woman, perhaps because it was easier financially in some cases, or because he liked her, or because he preferred to marry a foreigner (and slaves tended to be foreign), or some other reason. So it is a complicated situation.

This is apart from the fact that when people live close together, it is natural to develop an inclination towards each other.

When you look at classical literature from the Muslim world, you do see a lot of mentions of situations where a slave-girl and the man appear to have a had a genuinely close and affectionate relationship, and even many of the mothers of the Imams (A) also came to their households that way. 

So in that regard, it could increase social stability, even though no one likes being a slave.

Of course that is not everyone's situation and I am sure there were unfortunate situations of hatred and compulsion too. Still, it doesn't seem to be the same as it was, for instance, in the US, where Black slaves were regularly treated like animals and raped. Similarly today, in some countries, some people also hire live-in housemaids from other countries and sexually harass them like they are objects, which is both impermissible and also quite different from the above model which seems to have had more long-term stability. 

God knows best.