Things have changed 🙁 (advice)

About six months ago my boyfriend and I moved down south and both got new jobs, his taking up a lot more time than it used to. Since moving we’ve got engaged and are happily planning our life together. The only thing is, we don’t seem to be as physically close anymore. We don’t have sex often at all, he doesn’t ask me to join him in the shower anymore, and overall he doesn’t show me as much physical affection anymore. I don’t know if this is because of him being super tired after working all day, or the fact that he’s gained a little bit of weight and is insecure about it, but I don’t know what I should do. Please give me some advice.