Would I not be able to apply for a 2 bedroom for my son to live with me seeing as though he has additional needs and can't live independently?
There's two issues with this.
First. Proof. You need medical backup of this. Letters from social workers etc.
Second. Your son has two parents. If his other parent is happy for him to stay living there and is caring for your son not abusing him, then your son is neither homeless nor living alone.
With an allocation of need for a one bedroom place, you will likely have the opportunity to bid on two bedroom places too, but it's false hope and you are highly unlikely to get one of them. Perhaps you'll get lucky if nobody else in the correct banding bids for it. Realistically though, by bidding on two bedroom places, you're drastically extending the length of time you're in temporary accommodation.
Temporary accommodation isn't free. And it's expensive. If you're on housing benefit when living as a single person, you'll get special dispensation to have the rent covered by that, above and beyond the usual amount allowed, because it's not your choice to live there. If you have a job and aren't entitled to housing benefit, you'll have to pay the rental yourself. Benefits come from the government except housing benefit, which comes from the council. If the council are paying your rent they're not going to want you in temporary accommodation long term and you'll find if you're unsuccessful with bidding you'll probably be offered a direct let. That's where they don't put the property on the bidding list they just give it to someone of their choice. In my area you can refuse a maximum of two of these before they consider you to have made yourself voluntarily homeless, which would mean you being evicted from temporary accommodation.
All you can do is tell them about your son. Don't delay putting the application in, you can update details at any point. Get yourself on the lists and then start gathering evidence that your son should be housed with you. You may or may not be successful with that.
It's worth bearing in mind that living in a toxic environment will be affecting you son too. My advice is to take the help, get out by any means possible then offer your son a place to stay with you once that's possible. The alternative is both you and your son being trapped in a toxic environment long term.
If your temporary accommodation isn't very nice your son may be better off not being in that environment anyway. If you go into a women's refuge it will be safer and more supportive than some temporary accommodation can be, you'll be less stressed than in a bad place and so better able to help your son. Equally if you got given a one bedroom flat for temporary accommodation you could do as I said and let your son live with you in a bedsit each.
Sorry to be blunt but if you shy away from asking for help then nothing will change, one day you'll die of old age and you son will still be living with your husband (unless husband died first). You're not protecting him by staying, it's only a short term quick fix. You may as well sort it out once and for all by leaving now.
The alternative is to play the long game, which depending on your husband may or may not be possible. You can forget about him moving out. He's discovered from two nights sat in a hotel googling that he's got rights to the tenancy. As a single healthy man he knows he has no chance of being rehoused by the council, so he's hanging oni this cheap secure tenancy. Emotional abuse and coercive control is hard to prove. If you did manage to get it taken seriously by police and actions were taken against you husband, I personally think it's unlikely he'll be removed from the house (yes I'm cynical with little faith). When coercive control ceases to be effective it's common for abuse to ramp up and turn physical. Staying now your eyes have been opened and you've started standing up for yourself, isn't really an option in terms of your safety. But the alternative is to stay and play the long game. Women's Aid can help you make a plan for this if it's what you decide. You'll need a job (so would DH sabotage it preventing you from going so you're fired or take your wages?) and to get yourself into a position to move out into private rented accommodation.
I know all the options suck. The fucked up "silver lining" is this isn't just a relationship breakdown, it's DA which means the chance of a place in a refuge, more points for the bidding list and an acceptance that you're homeless (which you wouldn't otherwise be without the DA) so priority banding. I know it doesn't feel like much of a "golden ticket" but nevertheless it's one you possess and I'd use it to your advantage to get rehoused by the council if I were you.