How very lucky for you about the summer! How did it come about?

About your promise that he will be the only special person forever, you must either:

1. Tell him about its full meaning, including your suicide if he is gone, so that he can refuse your promise as he surely will, or, since you know your even the mention of your suicide will scar his young life, better

2. Destroy it yourself as invalid, since the very part that promises you to him (not just him to you) forever also takes you away forever - the promise completely contradicts itself and renders itself nothing.

Its underlying strain of avoiding feeling very bad for some time -- if it ever happens like that, get all the hugs you can, here and elsewhere, and if you are feeling suicidal, tell someone who can really help.