Your doctor's advice sounds harsh to me, although coming with the best of intentions. It is true that most people advise that your child should not be using teats after 12 mos, but there are many women on this site whose children do. I switched mine at around 12 mos from a bottle with a teat to a bottle with a toddler/sippy cup style spout. It still looked like the same bottle - might make the transition a bit easier? Or if he doesn't like a sippy cup maybe try him with no top on at all and you holding the cup?
If you are using formula at the moment I think you can switch to cows milk one of two ways - just do it straight away, or if you feel it will be a problem then you could mix formula and cow's milk together in the same bottle, and gradually down the formula and up the milk until they adjust. I used a different approach for each of my kids based on what I knew about their ability to adapt. And don't worry if it takes a few weeks to get there - there is no HARM in your child having formula after 12 mos, it's just that 12 mos is the first time they are able to drink cow's milk.
Many children can't self feed at 1 year using a spoon etc, so don't even begin to stress about that one!!! Just go at the pace of your child - they should be doing finger foods themselves, but feeding them yourself at this point is no problem at all. Encourage them to use a spoon too, alongside you.
As for ditching the jars, again I think this is a guidline, although they do sell toddler meals in jars!!!!! Just try and up the lumps and consistency and get rid of the really sloppy stuff. Some kids eat exactly the same as their parents at this age, some don't. Again I'd say just go with the flow.
I think your doctor was maybe just a bit forceful with his advice - it's all along the right lines, but you don't need to do everything at once, and go with the pace that your child sets, rather than some 'milestone' age you dr feels you are at.
Hope this helps - let us know how you get on.