People on this club who have 1.8 engines use a specific type of headgasket when repair is required. You can google on the search engine at the top.However judging by the mileage covered since the last change of gasket, you need to find someone who can do the job properly,as obviously it was not. When the head is off you will need to do a complete inspection of the head and block surfaces heights and firewall , and many other aspects. Its not just head off and replace the gasket,as you have now realised,but if you did try yourself 10/10 for effort. Try to find some one competent , there are people on here who can maybe recommend someone competent , as it needs to be done properly , otherwise you will be stripping down again ...
good luck !!