Keeping textbooks containing words that may affect one's beliefs

Q: I am a science student and I have a bunch of math textbooks. These are strictly math textbooks as I understand. In one of the books, the author mentions solving equations in their multiple variable "incarnations". I assume the author means "form" because there is no religious meaning here as far as I can tell. In a different book, the author tells a short biography of a mathematician who was also an astrologer. The presence of such words disturbs me. I would like to know if there is something wrong with me continuing to read these textbooks and can I keep them or not. 

Hadith regarding people who will come with mountains of good deeds that will be turned into scattered dust on the Day of Judgement

Q: I have recently read this Hadith:

Thawbaan (May Allah Ta'ala Be Pleased with him) narrated that the Prophet (SallAllahu 'Alayhi Wa Sallam), (May Allah Ta'ala Exalt his mention) said: "Indeed I know a type of people from my nation who would come on the Day of Judgement with good deeds as big as the mountains of Tihaamah, pure, but Allah will turn them into scattered dust." Thawbaan (May Allah Ta'ala Be Pleased with him) asked in fear: "O Prophet of Allah! Describe them to us, we fear to be amongst them while we do not know." Thereupon, the Prophet (SallAllahu `Alayhi Wa Sallam) (May Allah exalt his mention) said: "Indeed they are your brothers, and they perform acts of worship by night [prayers] in the same way you do, but when they are alone, they transgress the Limits of Allah." [Ibn Maajah and At-Tabaraani]

My question is this that does this Hadith include all types of sins and not just zina? Does it include listening to music, seing a non-mahram accidentally twice in public?

Forced Marriage

Q: I have been hearing that a forced marriage isn't valid. What does it actually mean? What if the couple in question have spent 20 years together and have children, after all these years, is their marriage still not valid?

I have basically spent the last 20 years crying continuously and praying to Allah to change my condition. I ask because I was forced into a marriage with a total stranger, moved to the US where I lived with his overbearing family for 10 years and subjected to extreme harassment and neglect from husband and in laws years before buying our own home. Although I begged him to move into a separate home earlier, he refused except for 1.5 years and then moved back to his parent’s home after being convinced by his mother.

My husband did not provide spending money to me from the beginning but handled all finances himself and hardly helped with childcare at home. I was embarrassed to ask him for any money even though I was completely dependent on him. My anger and hurt was too great. Once I started working, I contributed regularly to household expenses and childcare cost completely. Till date, I pay my portion of mortgage fully on car, food and some other bills while he pays for some of the others.

I have never felt taken care of as a wife, mentally, emotionally, physically, financially and I suffered a great deal spiritually for this. Physical intimacy has been minimal to zero from the very beginning as he is not able to perform as a man. We have zero connection emotionally, physically or intellectually and it has been and is just a living arrangement between two people where we each live together with our two daughters and take care of the regular chores to maintain a home. I think he is delusional that this is a marriage.

I have never been able to truly accept this marriage and have always felt that I will apply for divorce once my daughters have completed their bachelor’s degrees. It's not a life I would have chosen for myself, ever, and though I have tried my best to live a conflict free life, things have been difficult between us especially in the beginning. I have learned to emotionally shut off, shut him out and disengage from my husband to the point that I do not talk to him much and mostly when necessary. I've not been able to accept that it's what was written for me. I forgive my parents and I don't want my parents to have any punishments from Allah for this. I can't stand the thought of them suffering in this life never mind the next.

Does this make my marriage invalid? Considering how I truly feel, is it ok for me to wait another 4 years before seeking divorce?