Your not a bad mum at all. You did the right thing by looking for support. You and baby will get there soon. 
Don't be hard on yourself it just something you both need time to adjust to.
I'm sure someone will have an answer that works with your routine.
I've also had a rough week (or more I can't remember just how long it's been!) with my 18 month old he hasn't been very well either (cold, fever chest infection lots of ear pulling and scratching his nose 😢 norm for us when teething, then the actual teeth cutting through was hell he's been extremely clingy even in his sleep he just wanted mummy....I literally felt like I was cracking up.
Almost 2 months ago I had been trying to get him to sleep independently as he was ok taking naps alone during the day. So I figured he would settle easily in bed...I was wrong! I found it very difficult to get him used to going to sleep in his cot alone. I had previously been cuddling him to sleep in bed with me then would move him but a lot of the time he was waking up again all moody.
I purchased a projector that also plays lullabys doused the area around cot in lavender oil got a nightlight an we did eventually manage to crack it firstly with me in the room, just on my bed reading etc, breathing loudly enough for him to know I was there, then when he got into his projector I would leave for a few mins at a time (to make a cuppa) and quietly come in and out of room without making eye contact and later on managed to stay out all together) then boom, Hello teeth! Goodbye hard work.
Sometimes he will protest but I have to Ignore it, not that I'll leave him to seriously cry himself to sleep I personally couldn't do that. A bit of a moan here and there I can hack but not screaming. I've heard some people do it that way. Not my ideal but whatever works for them.
I do try to wait for signs of tiredness before I attempt to put him down though or he gets very distressed...there are no set bedtimes here, more of a realistic timeframe because my eldest has asd and is prone to random outbursts, I really need my other kids to be a bit more flexible at times so that's what works for us.
Some babies adapt better to a rigid routine.
Hopefully you'll find something that works for you. If not then continue co-sleeping if it means you get some rest too.
I'm wondering if your LO's ear infection could be teething related?
Anyway I do hope he feels better soon and also hope you get some lil snatches of rest here and there (let the house go to shit for now if you must, chill on the sofa with your boy you'll both appreciate it)
xx