Congrats gurnesy!
You have a smart lad there, and you won't regret it later, tough as it seems now.
My dd was very like this, and I just carried her for her first year: i carried her around all day long, and sang to her, and massaged her, and told her stories and talked to her constantly about what i was dojng, showed her things I was doing, fed her, and held her, and had her in the sling and just didn't put her down, even to go to the loo, even though she was 2 foot long when she was born, and I'm only 5'3", and she was heavy, very heavy!
It was exhausting, ill be honest, but I put her first and we muddled through. I learnt a lot about my self.
Basically I just gave and gave, and now that dd is older she really doesn't ask for much at all: she's very secure and self confident. Se only needed that intense level of care and attention for her first year. I'm glad I put in so much work with her and put myself second. My dd is a gifted and talented kid, in the top 3percentile. She's also a really nice easy going kid.
You will reap the rewards of putting in the work with him now - come on here to gripe about how exhausted you are, but be the best you can be for him, give him the human comfort he needs now to develop as a little human being. He's telling you what he needs, so it's your job to listen and give it to him. He's entirely dependant on you - he has no other mummy, it's just you who can give him what he needs from his mummy.
Go the extra mile with him, and you'll have no regrets. He will pay you back many fold if you put in the work with him now by being a fabulous kid, and I bet he's really smart.