Wa `alaykum As-Salamu waRahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
2- Some other scholars stipulate the company of a husband or mahram as mentioned in the prophetic statements.
Answering your question, Dr. Muhammad Salama, PhD, Islamic Studies in English, Assistant Professor at the Faculty of Islamic Sciences al-Madinah International University (Mediu), states:
There is a difference of opinion among scholars whether a Muslim woman may travel without a husband or mahram (non-marriageable relative).
A number of contemporary scholars have given preference to the opinion that allows women to travel without a husband or mahram but with a safe company, as in the modern form of trains, planes, etc.
However, there are other more conservative groups of scholars who stipulate the company of a husband or mahram as mentioned in the prophetic statements.
Second, for a Muslim woman, to travel alone and spend all this time without a husband or family is a risky endeavor.
You already live in a Western country and know the Western lifestyle, but at least you are under the protection and supervision of your family and soon you will get married, insha’Allah. I do not see the reasons you mentioned sufficient to legitimize your travel for work and be away from the family.
Let me here remind you of the Prophetic promise “You will never leave out something for the sake of Allah but that He will compensate you with something better.”
Allah Almighty knows best.