Dach, you poor thing! Kids can be pretty intuitive and i guess he knows something is about to happen, although he probably doen's understand what is going to happen.

Maybe you could try getting a favourite book and reading it to him in a quiet spot, or on the lounge and when it is finished he may not be so upset at you resting. or you could sit on the lounge with him and let him feel your belly (but you probably do that anyway). If you could get him a peaceful state of mind before you rest, he may not be so 'aggro' about it.

As for feeding the bubby and dealing with Yasin, I would set the kids up with some food or toys/books/pencils and paper etc to try to amuse them while i fed the baby. if he starts acting up, try to ignore him (unless he is doing something he really shouldn't be) or let him sit next to you and watch the baby feed. If you get up and run to him, you will interrupt the feed and have an upset baby as well.

Give him some 'big brother' jobs to do (if he can) while you feed, like fetching a bib or nappy or something to make him feel important

Don't worry too much about him being a bit 'put out' by the baby, because even the most well prepared toddler/child will feel a bit left out at times but they will soon adjust to the new sibling being around.