Finding a job, and now regretting all the opportunities I've passed up

If you would of told me 10 years ago, that this would be my life, I probably would of laughed and laughed. Ten years ago, I was just laid off and was getting ready to be on Unemployment while job searching, when an opportunity came my way I couldn't refuse. I took a job as a Warranty Service Manager at a Home Builder, and although I had NEVER done any work like that before, I was excited! I ended up working there for 3 1/2 years, moved up on the ladder and was making great money! Then I had my daughter, and my Hubby and I decided I could stay home with the kids for awhile, so I did. That lasted about a year and realized this was not going to be a permanent thing, I like to shop too much! So I went back to another homebuilder, where I was only there about 6 months. That company was nothing like the first one I'd worked for, so I just never looked forward to working everyday. But I always thought I'd be able to find another job.
Now here it is, about 5 years after that, and I cannot find a job for my life! I have done many types of work, Reception, Customer Service, Semi- Telemarketing, Warranty, Hotel work, so it's not like I'm just applying in one field of work. I think I've probably filled out at least 100 apps in the past 2 months, and I have recieved exactly ZERO calls back. Kind of makes me feel like I am no longer qualified to do anything but sit at home moping, being depressed and sweeping the floors.
And now is where I really wish I would of went back to school, for anything! After High school, I had planned on going to become a Dental Hygenist, but my fear of spit and pghlegm stopped that. Then after i had my son, I had decided to go back for Hospitality because I enjoyed working in the Hotel business so much. But then I found out I was pregnant with my daughter so I never went. Now, I've been thinking of going, but theres no money left to go. I've applied for grants and all that fun stuff, but I guess I'm just not going to get anything. I know all of this is my own fault, I just wish I would of actually thought of how good the future could of been, instead of this crappy life I've made for myself and my family.
Heres hoping that one day, my phone will ring and it will be someone wanting to hire me for a job, not just another bill collector looking for money!