My eldest very nearly broke me completely around that age with non-sleeping. She had problems with reflux (never medicated till she sort-of grew out of it - though I was horrified to discover when she was about 11 that some symptoms had continued to be part of her normal).
What you describe, having to feed to sleep and waking repeatedly in the night, sounds very similar to what I remember. In retrospect, I think she hadn't learned how to self-settle and instead of rousing slightly each sleep cycle and going back to sleep, every time she roused she would then wake completely.
The good news is, when I bit the bullet and decided I was ready to focus on helping her learn to fall asleep in her cot, her overnight sleep pattern was transformed within a few days - I hadn't expected how quickly things would improve nor the extent. (not saying we didn't still have night wakings but far far fewer)
So, my suggestions based on what worked for me.
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Think about what you are going to do, how you are going to do it, what you need to be able to do it. Until you've worked all of that out, give yourself permission to just keep coping as you are. The night I started, I had committed myself to this as my only priority for as long as it took.
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Have a set of "sleep cues" that you can use consistently. For us that was a combination of, verbal reassurance ("Mummy's here, time to go sleep" or somesuch), using a dummy, cuddly toy, and a wind-up music box. The latter was really useful I think, as you could turn it on and leave it to stop, and if you needed to go back in later you could just put it on again. We used that and also classical music CDs at bedtime for years. As a teenager she switched to audiobooks ...
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What I did was based on what felt reasonable - so leaving her to cry then returning wasn't an option for me. To start with I focussed on what I needed to change - which was for her to be able to fall asleep without being picked up. So I put her down and rested a hand on her. Then tried removing the hand. If she got upset, reassure verbally, hand back on her. Repeat, then try to move a little way from the cot. Etc till I was outside the door (short distance, it was a small room!). Like I was on a long piece of elastic, always ready to return, lie her back down, restart the music box, reassure, then gradually retreat if she was settled.
The thing that totally amazed me was how fast this worked for us. Within about 4 days ... I think when they are older than 9-10 months it can take a lot longer; but really hope that you can get good results rapidly too.
I think the total personal commitment helped as well; helped in having the patience to know I was going to stick with it, and probably helped me stay calmer than I might sometimes have been. It's a long time ago now so can't guarantee my recollections (DD currently overseas on a gap year lol). Remember that babies and children really value consistency. But also remember that we're none of us perfect and will always "slip up" sometimes no matter how noble our ideals and goals!
Very very best wishes for figuring out what "success" needs to look like for you and your son, and for rapid progress towards it once you have everything in place (externally and internally!) to be able to try. Sending thoughts of mental strength!