Oh, mama, I can empathize as my daughter was the same way and she was my first so I was completely clueless! I remember my usually helpful pedi calmly telling me that "Babies cry from 4 to 20 hours per day" and me wondering why I got the one that cries for 21 hours per day?!?!?!??!?! And let me tell you, my darling girl had some lungs on her! At the time it seemed mine never slept for more than 30 minutes...Which, of course, meant mama never slept for more than 30 minutes. Like yourself, my husband worked really long hours and we were new to the area so I had no family or friends that could give me a break. I felt trapped in the house as going out anywhere with a baby who was wailing 80% of the time was not much of an escape. Whenever my husband would return from work, I would immediately dash for the door to run to Target or anywhere for just a few minutes. Husband's big joke used to be "You're coming back, right?" I was so exhausted and mentally frazzled I thought I was going crazy.
IT GETS BETTER! It sounds like your lo has a combination of GERD/Acid Reflux and colic and both will pass eventually, but I never found much that sped up the process or seemed to make it better. At various times, I cut out just about everything - dairy, caffeine, broccoli, you name it- with limited improvement. The Zantac helped some.
What seemed to be most effective for me was to keep my daughter upright as much as possible - wearing her in a baby sling, in her car carrier, an electric swing when she got a little bigger. I even slept sitting up with her resting on my shoulder just to get a few minutes sleep. Being upright keeps that acid reflux from bubbling up as much. At about 3 months we started seeing some marked improvements and it was uphill from there.
As you can see, I don't have a whole lot of constructive advice aside from keeping baby upright, I just wanted you to know that you're not alone and that there is a light at the end of the tunnel! You'll make it there with your sanity mostly intact :) My "baby" just turned 10 so my memories of those trying months are a little hazy, but I wouldn't trade them or her for anything in the world. A big virtual hug to you, mama. Hope you get an opportunity for a nap soon!