Returning to the UK after being on a visitor's visa.

Hiya, hoping to get some help on this query.

I've been in the Uk for a year and a half, first on a year-long Tier 4 student visa, then I switched to a general, 6 month Visitor's Visa. I have been spending the past 5 months looking for a Tier 2 work sponsor, but nothing has worked out and due to lack of finances I unfortunately have to return to my home country (USA) a couple months before this visa ends. However, I have a life here, including a boyfriend, that I would like to visit as often as possible until I either find a sponsor (from looking from the US) or until he moves to the US.
I've tried googling this but haven't found much. Can someone explain if I have to be out of the country a certain amount of time before returning?

You aren't permitted to spend more time in the UK within a 12 month period than you spend in your home country.