Depression is common for heart patients in the first year. I have read that about 50% of patients suffer some degree of depression.
From your symptons- crying, sleeping problems- it sounds like you could be suffering from depression. You should discuss this with your GP. I have read that depression clears up within a year but can be treated with drugs or therapy or both.
I started feeling depressed about 3-4 weeks after my heart attack. I had trouble sleeping and had crying jags for no reasons. I talked to my Dr and she put me on Zoloft which was a IMMENSE help. It really made a difference in my life. My life started to get to normal within a week or so.
The other thing that help me was I started cardiac rehab.
If I was you, I would discuss my symtpons with my Dr as soon as possible. The Drs can really help most people in these situations. You have been through a lot with the bypass surgery. There is no need to add to it with the depression as the symtpons can be treated.