Help! Shattered middle aged/ancient first time single mum!

Hello, looking for some advice on how to get a good nights sleep for first time in nearly 2.5 years! My son has never slept particularly well but recently it’s become worse than ever and I am shattered. I sleep trained him just after he was 1 and that worked well for nearly a year ( when I say worked well , I mean he slept in his cot all night 4/5 nights a week but only until about 4.30am) and although 4.30 is so early I would happily go back to that -compared to what he does now 😂 about a month ago he suddenly refused to go in his cot, sleep training didn’t seem to work anymore, so I just gave up and just let him go to sleep in my bed. but that meant me going to bed at 7pm too! so 2 weeks ago I started a new bedtime routine , bottle and then I read to him until he falls asleep in his cot -which is working! woohoo one small win! now I need another! my problem is -he then wakes up a few hours later after I have gone to sleep-and I just go in and get him out of his cot and put him in my bed-and he goes straight back to sleep however then I barely sleep-as he is a right wriggler! He is waking up earlier and earlier-in the middle of the night and in the morning! 3.40am one day last week-I was falling asleep at work! so I think I know what I need to do-when he wakes in middle of night-settle him back down in his cot-and that is what I need advice on how to do it!!?? I don’t want to give him another bottle as at 2.5 years as I know I should be reducing his bottles not increasing them! Also I’m worried That if I did manage to re-settle him at 11.30 pm for example-will he then wake up again at 2am and 4am!? Or will he learn just to settle himself!? I think I could take a few nights of that if I knew that it wouldn’t last! Sorry for the extremely long boring message but wanted to put as much info as I could! 😂 thanks in advance for any advice!