I love books so I'll recommend a couple but really don't feel pushed to look at any books at all!
Three in a Bed - Very pro co sleeping. Explains about safety, benefits, that they won't do it forever, even sex - pretty much every one of the normal concerns people have. I loved this book so much.
The No Cry Sleep Solution This is sort of in the middle. It doesn't cover harsh sleep training methods but it's understanding if you're not 100% happy with co-sleeping either and will help you work towards a middle ground. Lots of suggestions rather than "This is the right way" so you can still follow instinct with it. (Although I do vaguely remember writing charts and charts for nights with this book which seems a bit bonkers, so maybe take it with a pinch of salt!)
What Mothers Do - Lastly, this is a beautiful, wonderful book. It won't tell you a single thing to do or give you any advice, what it will reassure you is that you're not alone.
And then some non-book reassurance and experience: DS slept with me from the day he was born. I converted a cot to a sidecar cot which was a perfect solution for me. XP wasn't super happy about him being in the bed so made up the cot for him when he was 2 months old and we tried him in there, he was happy to be a little bit away from me and scoot over for feeds, that worked really well. He was showing signs of being more independent at about 10-12 months (after a feed he'd roll over away from me before falling asleep, rather than falling asleep at the breast) but then I left XP so decided to keep DS in with me for reassurance/keeping the routine. Moved him out at 2.2 when he started stealing the duvet from me
He went into his own bed perfectly happily with not one issue at all.
Also on the dad issue, if you get the sidecar thing sorted out you'd have more room, and I have some lovely memories, both with XP when DS was tiny and everything was still OK(ish!) and with DH when DH when DS was older and we got together (I breastfed for a crazy long time, to explain the timescales) where I was feeding DS and had DH/XP cuddling me from behind like a whole-family cuddle kind of thing. And when I could only feed from one boob per side I used to roll DS over into the middle of us and after feeding him he would lie there and gurgle at both of us while we gazed at this amazing thing we made, and then I'd roll him back over my chest to the cot side again before we fell asleep. So I think it is possible for dads to be involved and quite a nice way to do that.