Oh L., I'm sorry. I'm sure you are so tired. OK, here are a few things that I used and still use with my 4 month old.
1. Miracle Blanket...WORTH EVERY PENNY!!! NO JOKE, IT IS A GREAT THING!!
2. Try to cut dairy out. My son doesn't have any issues with caffene or anything else, but if I have some milk it upsets him...not cheese or antything, just glasses of milk...of course, I normally drink lots of milk, but not anymore.
3. Gripe Water...get the Little Tummies one. I tried others and it doesn't taste very good. The only one that my son likes is the Little Tummies...it relieves those nasty hiccups immediately. Make sure and keep it in thre refrigerator
4. White Noise Machine...and have it LOUD
5. Bed time routine. I know they say you don't have to bathe your baby every day, but he likes baths and then we put him in clean PJ's, feed him a bottle/or breastfeed, swaddle him and put him to bed in. The nighttime routine works really well. We would sometimes rock him a bit if he was irritable...rock the baby while it is swaddled.
6. Pacifier...now, I thought I would never use one, but I am a fan. Now, at some point I will try to just have him have it at night, but he is still little and if he needs it then that is fine. He seemed to lose the big green one from the hospital, so we bought some newborn Nuk's from Target and those stayed in longer.
It is starting to get a bit cooler and I can not wait until it cools off a bit more. When it does, try to go for a late afternoon walk around the block in the stroller with a mosquito net over it. My son LOVES being outside and looking at the trees...plus it wastes some time instead of being cooped up in the house with a crying baby!
Good luck...hang in there...this crazy time will pass!
Hope this helps,