My XH worked away for most of a year. He’d come home once every 3 weeks for a couple of days. We both agreed on the move because it would help him advance his career, so a necessary evil. As it was, he got a taste of freedom (nothing untoward, just having only himself to worry about, free time for hobbies etc, a nice tidy house with no kids and no noise!). And I got a taste of independence, realised I could manage without him and that actually when he was home all we did was argue. It was the beginning of the end for us 
I’m sure some couples manage to make it work, but you need good communication when he’s away and teamwork when he’s home.
My current DP works away less regularly. We FaceTime every night and message throughout the day when he’s not here.
It did get a bit much at one point and I told him what happened with my ex and warned him we were heading the same way. I would miss him dreadfully for the first week but then after a while longer I got used to him being away and it would take me some time to get used to him again when he got back, he felt like a stranger to me. Plus he had to split his time at home between his DCs and seeing me, plus still working during the week. He was being pulled in so many directions and something had to give, which usually ended up being me.
He had to make a decision to reduce his work trips or split up,as it wasn’t sustainable for me. Especially as we aren’t married etc so his work success isn’t directly beneficial to me, as it would be if we were married and planning for a shared future together. Making the sacrifices of a long distance relationship without any of the benefits was just too much.
He’s away at the moment, but as it’s less frequent and the trips are usually a week or less, it’s much more manageable.
Sorry neither of my stories are very positive! Hope you sort things out. How long have you been together and has he always worked away?