@poppy8989 i think it sounds like you have tried too many things and now you and your son are confused and don’t know what to expect from each other when it comes to sleep.
7 months old routine
7am milk feed
8.30am breakfast of porridge and blueberries with a sippy cup of water
9.15-10am nap 1.
put him in his sleeping bag at 9.10. Make the room pitch dark and turn on the white noise machine. Give him one comforter. Put him down in his cot and walk out. If he does actual real crying, time him for exactly one minute then walk in and say shhhh it’s sleepy time, put your hand calmly on his chest and then repeat the phrase and walk out. Time two minutes and do exactly the same. Repeat as many times as needed. Do not do anything different when you go in and don’t give up. Don’t leave it longer than 2 mins.
Get him up at 10am. If he only went to sleep at 9.45, then get him up at 10.15 but not any later.
10.30am milk feed
12 o’clock lunch - including protein and with a sippy cup of water. Full fat Greek yogurt for dessert.
12.30-2.30 nap 2. You are going to do exactly the same things as for nap 1, in exactly the same order. No deviation whatsoever.
3pm milk feed and some baby biscuits or a fruit pouch
if nap 2 was rubbish, you can offer a short catnap in the buggy for 30 mins max between 4-5pm.
5pm dinner - carb based, avoid protein
6pm bath
6.30pm milk feed and bed, exactly the same procedure as for the two naps. No deviation.
i would only offer one milk feed in the night at 7 months and make it a small one. All settling do exactly the same as during the day. This is how you build trust when it comes to sleep. You are there, he is safe, and he will always know what to expect.