Hi Seansmammy and congratulations on the birth of your LO
I was going to just stop by and welcome you to the forums but now after reading your post I have to say more...
Please please please do not allow yourself to have thoughts of being a failure. You are absolutely NOT a failure! Wow, look how far you have come and what you have been through with a difficult birth, difficult feeding (every hour is utterly exhausting and you gave yourself to him to do this), you have devoted yourself and all your energies to this little being, what more could you possibly have done?
If you feel like having a cry go ahead, as a new mum you are allowed to cry, but no more feelings of failure!
Sleep training takes time, lots of time, and lots of effort, and your LO is still very very young. Don't worry, you will get there.
I would suggest looking first at how he was eating and sleeping prior to you beginning sleep training, for instance how long did he sleep and where did he sleep? If he has been used to feeding every hour or so you might need to gently increase the time between his E rather than jumping to 3hrs for a standard EASY routine. If he has been held for every sleep you might want to make a decision (along with DH) as to whether you want to go all out and go for sleep training at every S time (more effort and energy for you but likely to lead to self soothing more quickly) or if you want to go for one nap per day in the cot for now and work up to the others later (slightly less work for you as you just focus on the one nap but overall likely to take longer to get the entire routine in place with self soothing at every nap).
With regards to the sitting...Tracy said it takes 20 mins to fall to sleep. In the early days with my DS I could set the clock by this, it took exactly 20 mins, I could see the stages she described, the seven mile stare, the nodding. I discovered he needed a regular focal point for his seven mile stare and if I tried to change that (switch positions) he could not settle, I then realised I was holding him too long and the seven mile stare needed to be in his bed so that he could progress to nodding and falling asleep with his view unchanged. This also meant if he woke he saw exactly the same view and could return to his stare, nodding and falling back asleep.
Once he was sleeping independently I learned he did not like a long wind down. He liked to spend only a short time in my arms and then be put in his bed. At 10 weeks old he had quite a lot to say about where he slept and how long he should be held for. It took me some time to work out his cues, one of them was that he wanted putting down, I kept missing that.
Ask yourself why your LO doesn't like the sitting, what is he used to doing? If sitting helps relax him for just a minute or two then just do it for a minute or two, if he really hates it then I'd suggest either adapting it to something a little more familiar or skipping it.
Equally with being patted on his side, if there is an adaptation that works for you then do it, many of us adapt the methods to suit our LOs preferences. For instance would he be happier to be put on his back? You can pat his hip or nappy area. If he is used to falling to sleep in arms then I'd begin there, shush/pat all the way to sleep then put down asleep and continue to pat until he is in a deep sleep (20 mins). If he is used to being rocked in arms reduce the rocking and when drowsy put in his bed and continue to rock slightly by using a firm hand on him, even a small movement gives a little rocking. This is what I did as mine did not like patting and later I discovered he had silent reflux which the patting aggravated.
There is lots of support and information here, I hope you will find the forums as useful as I did when I found my way here 5 years ago
