Certainly your boys love their daddy and this is the important issue at stake when we are talking about the difference the children will find in your spiritual journey and in his. To ask if your efforts are worth the cost in terms of your time etc., I think it is equally important to address the issues from the standpoint of your husband's spiritual journey. All too often we think that only those who are called to far away countries etc. are true missionaries. However I believe that the first responsibility that we have in ministry is to the needs of our families. Your dear husband has in your sons and in yourself prayer warriors that will strive to bring him to the fullness of the faith.
You did not mention your husband's disposition. Is he an otherwise pleasant man? Is he openly hostile or rude to you or your sons because of your desire to practice your faith? To say that he does not support you in your faith can mean many different levels of support. If he is rude or openly hostile in any way then your issues are not with his spiritual journey but more importantly with your safety. Certainly you would be concerned with his faith journey but not at the expense of your safety or the safety of your children.
I am going to suggest that he more or less ignores your desire to be a practicing Catholic and your desire to lead your young sons to the fullness of the faith. He probably feels that your faith is a 'woman thing' and therefore not of his concern. It is surprising how many wonderful husbands feel that issues related to faith and spirituality are only concerns of women. They do not see prayer etc. as part of their life.
Your boys should not see your husband as a 'sinner'. This is harmful to their inherent desire to see their parent as good. The worst thing we can do is to destroy the image a young child holds of a parent that they love. There is time enough to explain his habit of cursing from the standpoint of 'sin' as they mature and are better able to understand more clearly how people sin or such. It is not good to speak in terms of sin when you are teaching young children. It is more important that you teach your boys how to pray for their father and love him despite his shortcomings. You should however gently and with respect to your husband tell your sons that cursing is not good for them to do.
One time I had the occasion to attend a Catholic homeschooling Mass to start the new school year. When it was time for the petitions to be offered Father asked for the children to offer up petitions. One small girl prayed that her daddy would come to know Jesus and become a Catholic. Her purity was so sincere that I was amazed and even more so when I realized later that her daddy was standing right next to her at the Mass. In conversation he was the most pleasant of men and I am certain that he was basically a good person who was blind at this moment in his life. I feel like his young daughter's prayers would be instrumental in bringing him to the faith.
I admire you very much and know that you are struggling under a great burden. Please rest in the knowledge that your efforts are not only 'worth the trouble' but are holy and sacrificial. Your sacrificial love and unselfish desire to bring your children and your husband to the faith is a gift of the highest degree. Remember that what you desire is what the Lord desires as well. Jesus' own strength will empower you and uphold you every step of the way.
Let us offer up our prayers this morning for all those families who must deal with faith issues. There are those families who find that their grown children have chosen to abandon the faith and it is for these families, Lord, that we pray and hope to intercede on their behalf. Guard and protect these dear ones each step of their journey. Amen.
Sending out a prayer,