JOEL - One of our main purposes for being here on this earth is to overcome weaknesses and hardships. In our pre-mortal life we agreed to come down here to earth to overcome those weaknesses so that we might be perfected and return to God. Therefore we all have different kinds of inherent weaknesses within us that are not of our own fault but are God-given. God, speaking to Ether in the Book of Mormon said,

"I give unto men weakness that they may be humble; and my grace is sufficient for all men that humble themselves before me; for if they humble themselves before me, and have faith in me, then will I make weak things become strong unto them."(Ether 12:27)

It is important to understand this if we are to understand how to control and overcome those weaknesses. Since God is the one who gave them to us, He is the one that can help us overcome them. But we are first required to be humble and to show faith in Him, as Ether recorded.
Everyone has burdens to carry in this life. Homosexuality is a very difficult one to understand and control. One needs to remember though that the sin is not in being homosexual, but in acting on those homosexual feelings that leads to sexual relations outside the bonds of marriage.

The jury is still out on exactly how much of homosexuality is attributed to nature and how much is caused by nurture. What is clear is that homosexuality results from an interaction of social, biological, and psychological factors. These factors may include temperament, personality traits, sexual abuse, familial factors, and treatment by one’s peers.
People can be unusually susceptible to other particular actions, reactions, or addictions. These susceptibilities can be inborn or acquired without personal choice or fault. One person may have feelings that draw him towards compulsive gambling. Another person may have a taste for tobacco and a susceptibility to its addiction. Still another may have an unusual attraction to alcohol and the vulnerability to alcoholism. Others may have a hot temper, a contentious manner, a covetous attitude, etc. And of course, some may have tendencies towards homosexual feelings. But regardless of our different susceptibilities or vulnerabilities, we remain responsible for the exercise of our agency in the thoughts we entertain and the behavior we choose. It is important for a person to recognize their own susceptibilities, and do everything they can to keep them from becoming a lifestyle.

Some things that LDS members have said that were helpful to them in overcoming, or at least coping with their homosexuality are;

1. The faith and prayers of those who love them
2. Their obedience to the principles of the gospel of Jesus Christ
3. A persistent therapist
4. The mercy and blessings and love of God.

Though homosexual attraction may not result from conscious choices, the divine gift of agency does provide us with choices in responding to such attraction.
Your friend praying to God to help take those "gay feelings" from him will help, but only if he will do all he can to fight it as well. Inactivity in the Church and lack of testimony of the gospel of Jesus Christ is a great hindrance. He really needs those things to help him either overcome the problem or to be able to live with it. Prophets of God have told us that a person can make such a change. A person with a strong testimony of the divine calling of a prophet, will have enough faith to believe them and know that they can change.
Getting involved in Church activity is sometimes difficult, because there are always a few judgmental members who will express their fear and lack of understanding by turning away from him or chastising him. God will judge them harshly for doing that. The Church is not a resort for the righteous. It is a hospital for the spiritually sick. That includes everyone to some degree for one problem or another. Homosexual behavior can not be accepted by the church, but your friend can be Mormon and he can be accepted and loved by the church and its members no matter what the problem is.
LDS Bishops have been trained on how to help members handle this problem and are aware of the types of help that can be given to someone. If his Bishop has not been of any help, it is possible that your friend has been unwilling to do the things that he has been advised to do, or perhaps it is because he lacks the faith to believe that it can help him. He first needs to work on his faith in God and his obedience and testimony of the Gospel. When those things improve he will have a much better chance.
Elder Richard G. Scott said,

“I cannot comprehend his power, his majesty, his perfections. But I do understand something of his love, his compassion, his mercy.
There is no burden he cannot lift.
There is no heart he cannot purify and fill with joy.
There is no life he cannot cleanse and restore when one is obedient to his teachings.”

This is a difficult subject with seemingly no clear-cut answers. But with God all things are possible. The process of changing takes time and is not without pain, but it can be done. If a person is not able to change the feelings they have, then they need to learn how to live with the problem without acting on those feelings. Keeping close to God and the Gospel can help them live a happy life no matter what happens.