If you don't mind me asking - you say you coparent with your ex every day. How does that work? If you don't want to deal with someone else's kid and have to see your own every day, why not get back with your kid's mom? If that's not possible, you could try finding a childless woman but it will be hard to find one who is ok with you going to your ex's every day. 

Please leave your partner immediately. No good can come from this.

"I held off dating because I thought no one would be ok with my situation. I think it turns out at no woman without kids would be ok at the end of the day..."

You aren't a "psycho" for wanting attention in a relationship. But you don't sound like you're ready to share a partner with any kids that aren't your own. So all you need to do is find a partner without kids who's willing to put up with your own co-parenting situation. Basically find someone who's willing to do what you're not prepared to do.

That is a lot to ask of someone else - who would take on someone else's special needs kid who will probaby never be independent?? Not to mention the constant interaction with your ex. But there is nothing wrong with being realistic and honest about what you can do. You are somewhat hypocritical so just own it. Best to move on.

You're not ready to date. Childless woman or a woman with 13 kids, 4 dogs, 6 cats, a rabbit, and a gerbil. You haven't done the work to get over your idealistic idea of what a family SHOULD to what your family WILL be.

It's unfair to ask a woman to join you in your life who is going to have her daily life dictated by the ex. I'm assuming you won't want to live more than 2 blocks from your son? Won't want to give up a week here or there to visit her family? Won't want to upset the ex because it was a bitter divorce?

You have created a life for yourself where your wants and needs matter more than someone else's. You WANT to see your son daily, and if you have to lay eyes on another kid before your own, you're upset? You want your GF to devote all her time to you, but as soon as she HAS to handle the NEEDS of her son, you become distant? 

I don't think your GF is starting to hate her son. I think you're unconsciously abusive. You disconnect when she takes care of her responsibilities, but then also think she's not doing her job correctly as a parent when she reacts poorly to your distancing. She's in a no-win situation with you in regards to her parenting. You're mad because she parents, but then mad when she doesn't.

Look, right or wrong, you ex left you. That means you can either build a new, differently life or you can cling to what you can of the old for normalcy. The former comes with the opportunity to date and show your son that different isn't bad. The latter comes with not dating. It's unfair to ask another adult to bend and mold themselves into a slot in your life where they no longer exist as a separate person, but only as "your partner". I'm not saying you can't have expectations, but those expectations can't be so rigid that anything outside of them is met with indifference and disconnection from you.

In conclusion, you need to work out how to be a partner. What have you done to better yourself since your divorce? Any therapy? Read any self-help books? Do some internal reflection on how you got to be on the outside of a marriage? Discovered where you could improve as a partner? Do that work, and maybe you'll be ready for an adult relationship.

You mean you held off dating until you found someone with low enough self esteem to put up with your... ridiculousness (best word I could come up with that was halfway nice).

Immagine, for a moment, your SO's life with you. You have a high demand special needs kid and are hip deep in coparenting and enmeshment with your XW who lives just down the street.  An SO will get no reprieve from your life. Ever. You in all liklihood will be coparenting and enmeshed with your XW for the rest of your life. Then there are the facts that you want your SO to ignore her own kid for your benefit and you are dick to a 4yo. smh

.  What about this makes you a catch?

I truly hope that your SO gains clarity and cuts you loose soon in order to save herself and her child from your crappy presence.  

Please, do not rope in another woman to be the sacrificial lamb on the alter to your failed family and the life long burden of your special needs child.

Find an escort service, set up a account, and deal with your need for companionship that way.  Do not ruin the life of anyone else with your clueless, completely self serving, flawed perspective on relationshops.

Good luck.

All IMHO of course.