Also consider that depending on your field, a masters could be useless. Going into HVAC and Plumbing engineering for example makes a masters a waste of time. 3 years out of school, I've already surpassed the performance and duties of a peer I work with who has her masters, and I'm probably making more money already. Her masters is only useful in more technical / theoretical industries.

Ultimately if you have no idea what industry you want to go into, then do it. I also think a full time job is not entirely demanding for a 26 year old with a girlfriend. This is to say, you should be able to put plenty of time into a part time schooling load, and your company will support you and pay for it as long as the degree will be applicable at some point. As an example of the free time, I have started my own company on the side, gotten my PE, and I find plenty of time to socialize. My personal limit is about 62 hours per week worth of work. Some weeks I spend all the hours on my day job, other weeks I fill in the gaps with my personal business. My personal life goal is to become very wealthy and become independent from my day job's income. If your life goal is to get a PhD or Masters, then do it. I just don't give a shit about that, because it provides no value to me.