Problem with my hubby???????????

Ok I have been married for two yrs with my hubby, we have had major problems and have separated twice. I have been back for 2 months had a baby she is 5 months. Well the problem is we have had sex only twice in these two months and that is soooo not normal for us, and a couple days ago I heard him masturbating in the bathroom and yesterday also.... What is going on, he says Im attracted still and he loves me but than why do that.... I tlod him I heard him the first time and he soo dinied it, I have not said the second time. Thank u