I have been told that I must be sealed to my non LDS husband who was anti the church for me to obtain the celestial Kingdom. Is this true? I have done his work except for the sealing.
The ordinance of sealing is the only ordinance that involves a third person which from time to time make people confused on what is really going on. In other ordinances (like baptism) it is between us and the Lord and we alone live up to the covenants or fail to live up to them. We then must deal with the consequences of our choices and actions. We alone make the choice to even enter into the covenant.
With sealing we add a spouse.. A spouse clearly has an impact on our lives and our ability to enter into and keep a sealing ordinance and live those covenants. Yet it does not change the fundamental fact that all gospel covenants are between us and the Lord. We are responsible for seeking out and living the ordinances and covenants of God as best as we can given our circumstances.
When your husband was alive he was ineligible for the temple ordinance, and since you were required to have your spouse present, receiving the sealing ordinance fell in to the category of things you could not do. The best you could to was to practice long suffering, kindness as you worked with your husband to try to bring him to Christ.
Then he passed on. You had no trouble having all the other ordinances done on his behalf, knowing that they would only be effective if he had a change of heart and accepted them. Why should you think the sealing ordinance is any less important for him to have? For you to have?
Perhaps at some level you are afraid that he will not change? (You are in a better position to judge that then I) Perhaps you feel that if you seal yourself to your deceased husband and he does not change you will also be denied? If those are your concerns then I would extort you to exercise your faith in Christ’s promises more fully. Christ will not deny anyone who works and acts in full faith in following his commandments any blessing. When it comes to sealing when one spouse is not worthy, Christ will make it right for the other spouse.
Your situation seems quite clear. You need to seek out the ordinance of sealing for your own blessings and you need to do the work for your departed husband. Logically the two things answer each other (which is why people are telling you what they are), but the Lord is the one you should be seeking for guidance and ultimately you will need to trust the Lord to take care of the things you have no control over.