how to cheer up in best way?

recently i feel very stress cos my bf is in low tide period... he always speechless when i ask him questions~ maybe he facing some kind of problem but don't wanna share with me but properly will be financial problem... he just went for his driving lesson and his ex gf sending him some text message at the same time and say something bad to spoil his mood... until today his mood didn't seen so right and when ever i say something his answer not more than 3 words... we are long distance relationship... cos i study oversea and he working in our country...

beside that when ever he have problem he use to keep itself because he don't wanna make me worry too much some more im far from him...

i wonder have anyway to let him know i care about him but not letting him misunderstand i "controlling" him...

P/S: im going back to my country in 15 days...