OP,
So you have told him that you don't want sex:-
''not appealing for me as haven't been made to feel special''
and he has gone out and bought one of these fleshlight things
Perhaps give him a little credit for realising that keep on pressuring you for sex is not going well so he has taken steps to remove this pressure.
Although, can I just ask have you thought about how much this is you ''not feeling special'' and how much it is you, perhaps subconsciously, restricting sex with your DH as a punishment for his lack of involvement with the home and children?
Men can be rather strange about this and it can easily get into a downward spiral. You feel neglected and so don't feel like having sex. He then gets a lot less sex and so this makes him feel neglected which then affects his relationship with you which then makes you feel even more neglected which means you feel even less like sex etc etc.
This is made an awful lot worse if he feels that you are withholding sex in order to punish him. You may well not be, but that could certainly be how he interprets things.
As foolonthehill said above, you really do need to do a lot more communicating with each other and perhaps some external counselling may well help.