You will not like what I'm writing, nevertheless I think you should know this.
Your husband has said Cheryl loves him in a way you didn't, you love him in a way she can't, he loves both of you and mother dearest pushed him and Cheryl together.
Your husband wants to eat his cake and have it too! His mother doesn't control his feelings toward Cheryl or you even if she did push them together.
The person at fault for loving Cheryl is YOUR HUSBAND! You need to take control of you and only you and accept that if your husband wanted to be with you, he would be!
You can make this easy or hard for yourself...easy would be to simply move out the way and let him, YOUR HUSBAND, choose the person he loves and want to be with, this way you'll know where he's stands emotionally with you.
Hard would be what you and Cheryl are doing now and he's just sitting back loving every minute of having two women want him at the same time; fighting over him while he gets to do what he wants!
Make your mind up to let him choose with you not standing in his way, then you'll SOON see who he wants.