SO confuses me..

I've been with my guy since September and we've been really good for the most part until recently since he's been busy and stressed with work.. he'll take his frustrations out on me and ignore me for a day or 2. we'll make up & I think everything is fine until it happens again (it's only happened twice) were both stubborn so neither likes to text first after these arguments.. I just don't know what to do or say to him that won't stress him out more than he is. & before anyone says he has other girls on the side hes literally NOT like that. I miss him and I want this to work for us but idk what to do. Any tips or advice would help.