Goodbye letter to a boyfriend or girlfriend is always a good gesture and makes a good impression regarding graciousness towards your partner. Going away or just leaving for study abroad sometimes is tough choice to make but still when someone separates for a certain period, it is good to describe your deep emotions in written form and a goodbye letter makes perfect sense.
A well written goodbye letter sometimes contain very heart touching lines as you want to make your partner believe that wherever you will go, you will always feel the same for her or him and will never leave.
In the first paragraph, you should mention the reason why you are writing this letter. Give details about how you feel towards your boyfriend.
In the second paragraph, mention where you are going and why you need to let your partner know. This is important that it gives a very soothing feeling as to how someone cares for his or her partner.
In the last paragraph, mention your love for your boyfriend and end the letter on a good note.