Ex has up and moved

Hi , completely new too this but hoping for some advice , I have struggled with my ex for years , he's had two contact orders put in place and changed them within months of being given them (over four years ) then I had too apply too the courts too take them aboard on hols as he refused permission 8 months ago (which he asked for extra contact that was given by me ) (I have no desire too stop contact just would like consisitincy ) and then April he talked my eldest into moving in with him and his wife due to exams and it being more peaceful (which I agreed ) too then completely turn him against me ...and then move too Middle East stopping all child support (that's the only reason he had my son (he claims child for child and I'm a lazy cow ) now I'm not being greedy given there £75k wage and would just like the sum cms stated of £300 . It's not a REMO country , his wife is still here in the uk with my son (so I'm still liable for cms ) and I quite possibly will be loosing my house due to the now short fall in rent ! I do work I work 16 hours in school time as all other jobs I've had he's interfered with and am looking for extra work also but with the universal credit wait and no child support this I struggle with . My question I suppose is if I apply too the courts will they even consider a application from me without him being here ? And although not enforceable in his country could I with hold it here ? my son who lives with him is 17 looks after himself and earns a wage between school , I have no problem helping support him , but my youngest is 7 and takes a lot more arranging etc and limits my jobs ...please no bashing I just need some help to keep a roof over our heads X