Need suggestions on doing PhD or not I am having a hard time deciding if I should go on for a PhD program after my current Master's program. I'm struggling with this a lot and hope to get some suggestions here.

So my situation: I'm doing a second Master's degree in mathematics after finishing my first Master's degree in Engineering. My current university doesn't have a very good ranking, so I'm considering a PhD offer from a university ranked around 160. I want to do research, but my biggest concern is that I'm 29 y/o, after finishing my PhD degree, I would be around 33-34. And I don't have a girlfriend. So by the time I finish my PhD degree, I would have no money, no girlfriend and not clear future, I might be single forever. This sounds so miserable. But the bright side is that I will have a PhD degree from a better university. And this might open more doors for me, I might even be able to go to Google with this PhD degree after graduation. And since I will work on hot CS topics, the professor said he is confident I will have many opportunities in both industry and academy after graduation. But of course there is no guarantee for anything. Though it's somewhat reasonable because I only have two years' background in computing, all my previous background is in civil engineering, I don't know how far I can go in computer science industry without a real degree in CS. On the other hand, if I decide to get a job instead, I can make some money first. And when I have money, I can secure myself and will have more chances to get a girlfriend, and financially easier to get married. Also since I will then have relevant working experience, it might even be easier for me to apply for many more top-tired American PhD programs? But of course this is only my imagination, I might end up losing this valuable PhD offer and not be able to get a better one by then?

Thanks a lot for your time and hope to get some kind advises!
Don't do it.

It sounds like you don't know why you want to do a PhD. You focus on things that aren't reasons, and where you do mention reasons they are very vague, e.g. in a comment you've said that:


  But I will have also opportunities to intern at national labs during my PhD, would that be helpful for my post-graduate career? And their math program is top 50 in QS ranking, sounds so attractive. And I do love research, the main issue is I'm too old and have no money.


First sentence ends with a question mark indicating you aren't sure it's true. You clearly can't make decisions if you don't know if it's true, so you should find out first before even thinking about the question. Second sentence indicates you want to study at that university simply because it's in the top 50 in the QS ranking, which is fine (I suppose we all have different priorities), but are you sure it's worth it? There's a high cost to studying: you earn less (if you earn anything at all), you spend time, you have to relocate, and so on. The same goes for the third sentence. If you're too old and have no money, why are you considering a PhD?

My read of your question is that you're studying because you have no idea what to do next and / or want to avoid the job market, which is not a good place to be. You'll have to get a job eventually - even if you do a PhD, you'll eventually finish the PhD and have to find something else. Until you've figured out what a PhD allows you to do that you can't do now, you should not do it.