To sleep train or not to sleep train, that is the question..........?

My 7 1/2 month old son has always been hard to get to sleep. It takes forever to rock him or cuddle him to sleep, and most of the time he gets full before he falls asleep and won't take the bottle or the pacifier. I was desperate and tried sleep training, and he did ok for a few days and now it's just plain torture on all of us. You would think that after 7 1/2 months, I would have found a way to get my baby to sleep with out much of a fuss. Like I said, rocking takes a long time, and when he gets close to sleep, he fights against it and tries to wiggle out of my arms. The same with just plain holding him and cuddling, it's less of a workout for me and he still tries to wiggle free. I've tried the soothing him in his bed thing, he gets mad. So, in desperation, I tried a modified Ferber sleep-training and he was good for the first few days, it looked like it was working and then he relapsed really bad with even more forceful and longer crying than before. Today, he was fussy and whiny all day long, and going to bed was torture. I'm getting pressure to sleep train my baby because well meaning family members claim that he should be falling asleep by himself by now and if I don't get him falling asleep on his own soon, he's going to have sleep problems for a long time. Is that a bunch on BS? Or is there truth to their claim? I really don't have the heart to hear my baby cry. He had health issues when he was born, with a lot of needle pokes and IV's and stuff like that and did a lot of painful screaming cries when he was first born, and it physically makes me sick to hear him cry. I'm torn because, a lot of people I know say that my baby is too dependent on me and I'm spoiling him and he needs to learn to handle things on his own and be used to other people. I'm having a emotionally bad day today I guess and would love some answers. Of course, I feel like the wicked witch of the west for attempting sleep training and have this terrible fear of causing my son mental and emotional damage from that attempt. Are a few days of sleep training emotionally damaging? I'm rambling now. I'm having a very much doubting myself day.