Hi,
These are the problems that mums who stay with kids also face but yes, you must have noticed his different behaviour and you are anxious. I think, all this no doubt is happening because of his frustration of you not being around. I suggest, firstly never try to get gifts to fill up your guilt. That may make you and him good for a while but that will spoil his psyche. Secondly, when you are home, spend as much time with him and try to tell him in a baby way why you are out and cannot stay together. When you have to do something and have no other option the best way is to be honest be with your children no matter how small or big they are. This way, they will atleast try to understand what you are saying which otherwise they wouldn't have any idea about.
Magbasa pa