I have always been against love spells for this reason..It is forcing someone to go against their free will. That being said there is a way to do it and that is write your spell asking the universe to bring your soul mate/ true love to you. That way your not forcing anyone to go against their free will.
From your question it seems you need more study before you will be prepared to cast successfully. It is indeed a good idea to write your own spells, but only if you know the basics of magic and spell crafting well enough to do so. In our forums so far in the last few days i see a request for a luck spell for beginners, a request for a spell "without candles and that other stuff, just basic",and a request for help becomming a telepath. I see this sort of thing often with newbies....you have discovered the craft and this wonderful magical path and you want to be it all and do it all RIGHT NOW! Take a deep breath and settle down...the craft, like most worthwhile things takes time and effort. Many dont mind the effort, but most hate the time...patience is one of the first things a serious student of the craft will learn. Attempting to cast before proficiency at the basics of magic tends to turn out one of two ways...most common for older students will be a loss of interest due to a lack of results, for younger students with more vivid imaginations it tends to lead down the fluff trail of magical make believe. Once you understand how magic works, learn correspondences, and become proficient at energy work you will be able to write your own spells and cast them successfully as long as you hold to your most essential magical tools...common sense, maturity, and intelligence.
try using a rose quartz and some attraction oil in your spell...good luck...i also suggest that you should slowly start releasing the spell every day when you guys get together so that when the spell is fully off they will not leave you because they will have developed their own feelings.