I love Krishna and am very eager to have His darshan. While I am motivated to engage with Him, I get disturbed by Kama (lust) which strikes me hard. Please advise me a method to win over ‘kama’.

Don’t worry. Just like hunger and thirst, lust is also inborn. No doubt, we have to overcome it. But it is not as easy as we think. It will not be gone one fine morning. It will happen slowly and will take time. Constant prayers and chanting will help this happen.

I have been chanting Maha mantra daily for the past six months. But my sexual desires and arrogance are getting increased. What should I do?

Continue what you are doing right now. The rest of the things will be taken care of automatically. If possible, increase your chanting.
Once a similar question was asked to Bhagavan Ramana. Bhagavan replied, “If the fort is to be captured, firstly all the soldiers from inside the fort should be allowed to come out and be killed one by one. Likewise, it is only your Vasanas (impressions) that are manifesting themselves. So there is nothing to worry. However, don’t stop chanting for any reason.

I am not able to control my lust. Please suggest me a way so that I can practice Brahmacharya and attain the Lord.

Lust is human nature. It is unavoidable. Eradicating it completely is not an easy task. So you don’t need to feel guilty if you are not able to practice pure Brahmacharya. If you want to overcome lust and practice pure celibacy, try to adopt the following:
Practice strict diet and consume only saatvik foods, that too, only after offering it to Lord Krishna
Perform simple breathe control technique – Pranayam
Keep away from all possible distractions such as opposite sex, movies, novels which potentially trigger the feelings of lust in your mind.
Perform Maha mantra kirtan always and pray to the Lord sincerely to help you out.
It is a slow process. You will not be able to wake up one fine morning to find yourself free from lust. So be patient and practice the above. With these procedures you will definitely be able to control lust.