sorry i doubt the sincerity of your boyfriend, if he is really prepared to give up everything then get a divorce straight away,...now, if he is afraid that the children will be taken out of the country then he can file a petition to the court for the surrender of the childrens passport (if he really fears that they'll be taken out of him)...
anyway, the law here is so different than in the PH , since you said that your bf is prepared to give up everything for you , after the divorce , it doesnt stop him paying the child maintenance/child support for the kids which is both under 16.
It is illegal to neglect your responsibilities in the UK.