Hi - like JC, I would need to know how old your son is. I did have a baby with colic, but this was when he was an infant. In the end, we figured some stuff out.
I also had periods of a week or two where my kids all were fussy in the evenings. That passed.
What are the 5 S's? Mine are a bit older so I might be out of touch :)
ETA: Thanks for the added info. Ok, now remember the 5 s's! That takes me back.
My first born had colic. We tried everything - those gas drops, me making sure I wasn't eating anything that would make him possibly gassy (I breastfed), etc.
I did not have a bouncy seat that vibrated for him. With my others, it was a lifesaver. I used to walk him in his stroller, and at night my husband would walk him in his car seat (swinging it up and down our hallway), we'd go for drives, etc. He liked the sound of running water (it would soothe him) so if nothing else, I'd run the tub. It was very hard. I remember.
I went and had him completely checked out to make sure it wasn't anything physical. She told me about a book where you had a system, wake, feed, play, nap - and said he'd do better on a strict routine. In a way it worked, but I felt chained to the clock, being rested helped him from getting fussy, but he wouldn't sleep at night because he was sleeping so much during the day. So - it was one or the other. In the end, I biffed the book and just did what felt right.
The only thing looking back that we didn't really know about was our son had bad ears - fluid in them. He ended up needing tubes. I've always wondered if the excess fluid was bugging him at that very young age. Just something to consider.
My best suggestion would be to get help for you (someone to take him) because you will feel emotionally drained. It's ok to take a break if you absolutely have to. A few times I had to put him in his crib and he cried while I took a few minutes to myself. I felt terrible doing it, but I felt I had no choice. Bouncy vibrating seats and swings are a must. Some like carrying them in a snugli.
It will go away - just when I thought motherhood was for the birds, it got easier. It's not you - it just happens to some babies.