((((HUGS))) Michelle.
Sleep training/getting back on track after illness is so so hard. It's difficult to find the right balance between loving/caring and consistency, but it sounds to me like you are doing really well.
T has obviously had a rough time lately and needs you close by to provide him with the comfort, security and confidence to fall asleep. It IS a hard task to convince him that he can feel all of these things from the comfort of his own bed too!
A couple of thoughts. When we went thru sep anxiety I put some of my clothes in the cot with Ciara. I think I used a PJ top, so it was big enough to stretch across the matress and be safely tucked in, iykwim? I think the smell and the familiarity of the material was often enough to settle her initially and prevent that frightened stage from ever really appearing. So it was just falling asleep we had to deal with rather than an anxious lo + falling asleep.
When Ciara came out of hospital after a week in a hospital bed, we had a lot of playtime in her bedroom and in the bed, so that she got to enjoy being there again, and didn't see it as a place she was being put then abandoned. I'm sure we also introduced an 'in bed routine'. So bedtime routine, then special in bed routine - story, cuddle, music etc. Ciara was about 2 then, so not sure how well it would work for T as he is younger.
You are doing so well, try not to be down on yourself or over critical. Yes, rocking to sleep isn't ideal but if you have a poorly baby, the most important thing is to love and pamper them, and deal with the rest tomorrow!
Love to you