A general background: I'm working as a test engineer at a pretty established and well known engineering company which is located in my hometown. My girlfriend, who is also an engineer is working in another company in her own hometown which is around 8 hours away from mine which is quite far.
This is my first job after graduating and have been working here for 5 months. The pay is decent, the work culture is great and I'm generally very comfortable working here. However, my girlfriend and I have been planning to move in together. The catch is that she wants to be near to her single mom is so that we can visit her during the weekends. I have no problem with this as I'm comfortable leaving home. We planned to move to the capital of my country which is around 1.5 hours from her hometown.
I planned to leave my job around December 2018. So, 1 year and a half will be the time spent working in my current company. Honestly, I am beginning to have second thoughts as I really like working here and believe it has good career opportunities. Not to mention the lower cost of living compared to the capital. My girlfriend refuse to move to my hometown as it is simply to distant from her mom so that's out of the question. I have tried convincing her many times but it was not successful.
Besides that, my manager is having the mindset that I will be staying in this company for a long time. He has been sending me for training classes and conferences, entrusting me with critical products of the company and in general grooming me to be a long term employee. I have not told him about my plans.
So my question is will this move affect my career and learning opportunities? Should I continue with the plan or should I stay longer here? I'm afraid my manager will be really disappointed if I tell him one day that I want to leave so soon but on the other hand I really want move in with my girlfriend.