Married, truly seeking advice ladies..

I have been married for two years, been together for over three. We have a 15 month daughter, and overall I should be incredibly happy, and for the most part I truly am other than the sex. 
Before my husband, I had a lot of sexual experience and he had none, we were both open about it, and he knows everything about my past as I know of his. I honest to God love this man, and truly honor how sacred marriage is. Before being with him, I have been cheated on, as well as constantly cheated on my exes. I know it was wrong, but l have been honest and true with my hubby, he know about the way I was. 
At first our sex was good, passionate, and even though he isn't big down there, I never cared due to my feelings for him.
Lately, i have been so unsatisfied and sexually frustrated. I have been irritant and moody and am always wanting to have sex but he's always not on the same page, and I know it's because of work and whatnot, that he's tired but I always make sure he is constantly satisfied. 
Overall this has been happening for A few months.and I've already been dealing with depression for a while but this came out of nowhere.. Sex has never been an issue.
I've felt tempted to cheat but every time the thought comes to my head o tell him, I've also talked to him many many times but still nothing....idk what to do, it's honestly frustrating, I will not cheat on him regardless, but for someone who's always had an incredibly high sex drive, I'm unable to keep it in much longer.