25 year old going back to school for Engineering... thoughts? Advice?

I'm 25 years old and will be 26 by the time I start school again in September.

Anyway, a quick backstory: I did college (Business) out of highschool, graduated college at 21 but never really found a job I liked. I've always had some interest in engineering but never had the requirements to be accepted into university. I slacked in highschool and math was never my strength.

Now, I decided I want to go to university and study to become an engineer. I'm doing the 4 highschool requirements I need, online through correspondence.

I want to do it... but I'm unsure if I can. I'm older now and I don't know if I can put up with another 4-5 years of being broke, especially in my late 20s. I'm going to have to take out a loan, and this is also going to suck out my social life. At the same time, it's just another 4 or 5 years to give me something I can use for the rest of my life.

Are there any other mature students out there with a similar situation? How do I convince myself I'm making the right decision? I know I can do the work, I just lost the motivation but at the same time, I really don't have any career choices so I figure going back to school is the best option in the long run.