\You are mixing up 2 distinct issues. One, does the RCC believe that homosexuality is a sin. If not they should agree to gay marriage. Two, chastity is not possible for homosexuals. It is a contradiction in terms. So long as the RCC tries to normalize homosexuality and make it chaste they will continue ordaining gay priests and will skirt dangerously close to making sin a sacrament.
Homosexuality, if you mean the temptation, is a temptation, not a sin in itself but always a moral danger, due to our fallen nature.
Is it possible for a person who experiences this temptation, to live chastely? Yes, it is. By rejecting the sin in thought, words, and deed; by avoiding the persons, places, and circumstances which conduce to this sin; and by a firm reliance on the grace of God and recourse to the Sacraments.
1 Corinthians 10:13
No temptation has overtaken you except such as is common to man; but God is faithful, who will not allow you to be tempted beyond what you are able, but with the temptation will also make the way of escape, that you may be able to bear it.
This applies to people battling temptations to homosexuality, or alcoholism, or gluttony, or wrath, or avarice, or thievery, or sloth, or marital infidelity, or any other sin.
It is important to make a distinction between the temptation, and the sin.
The Catholic doctrines have never, as you say, "normalized" homosexuality.
There are way too many ignorant, deluded, or proudly dissident Catholics in error about this, but it is their opinion, and not Catholic doctrine, which is erroneous.