Any advice please

My 8 month old caught hfmd from my 2.5yo for the THIRD time. He has many ulcers on his throat n a fever. He doesn't go to IFC but his sister attends CC. My 2.5yo only has some blisters on her hands n feet, no ulcer or fever which I'm thankful for. My 8mo was hospitalised twice due to the previous HFMD period, 1st was due to him being only 2mo n 2nd was due to dehydration. He had to have a NG tube put in. I'm really dreading this as I don't wish for him to have to go back to the hospital again 🥴 He's still drinking milk as of now but his intake has definitely dropped. I gave fever meds too. Is there anything I can do to help him feel better? He's also extra extra cranky whenever he's sick.