HELP!?

I don't know how or where to start.... I am 27 and have been with my significant other for about 8 years now. He has two kids with his past marriage. We have a 2 year old daughter together. I am currently working full-time and I go to school online. I have hit rock bottom and I am not sure if I am depressed or just tired. I have been so emotional lately and I thought I was pregnant because my period didn't show up in March,but I kept testing negative. I got my period yesterday. I guess work, school, kids, hubby, house duties, and many other things have me stressed and exhausted! I literally cry over everything! EVERYTHING!!!! We have been trying for a baby...for about 6 months now. That has me so sad also because I feel like I am just getting older by the day and No baby! 😢 Am I crazy!? 💔