The rule about Jannah is that you will have whatever you want then, at that time in Jannah. So if you want to look a certain way, provided Allah admits you into Jannah, then you will be able to have that. By default all of the men in Jannah are handsome and all of the women in Jannah are beautiful, but if there is something specific then that you would want then that would be no problem as Allah told us that the inhabitants of Paradise will have whatever they desire and that is easy for Allah.
It is a duty upon us to make clear that Allah has made Paradise open only to those of true faith. True faith consists of worshipping Allah alone, with no partners or sons, and to follow (as much as one can) the teachings of His final Messenger (May Allah's Peace and Blessings be Upon Him). To believe in the Messengers (all of them) and to believe in His Books (all of them) including the Quran which is Allah's final revelation. Whoever does all of this, Allah has promised paradise for that person, and Allah never fails in His Promise. Whoever becomes a Muslim, Allah will obliterate their past sins and within Islam, there is an abundant variety of good deeds that one can do to increase their share in the Afterlife and earn a high exalted level enjoying nearness to the Throne of ar-Rahman(The Merciful).
One should be very careful never to attribute injustice to Allah. Allah's favors on each and every single one of us are uncountable. Allah compensates always. If Allah deprives a person of a certain blessing or favor that He has Given to others, then that one will have something that others don't have. For every blessing, there is the responsibility of gratitude upon the one who has received it. How many people have been given an abundance of favors from Allah but return that with ingratitude? Be grateful for the favors that Allah has given you (which are many) and Allah will give you more and anything you miss out on in Dunya, you will never be deprived of in Jannah, provided you are a Muslima who believes in Allah and His Messengers and who strives (while making mistakes) to worship Allah alone.
I apologize, I'm a little confused. It says in your profile that the religion is Christianity but you say you want to be a good Muslim. If you have taken the Shahadah already, then al-Hamdullilah, All praise is due to Allah and welcome to Islam. I hope that Allah ('Azza wa Jal) Guides you further and makes you live and die as a good strong Muslim. If you have yet to take the Shahadah, then I strongly encourage you to do so. If it is difficult due to obstacles of any sort then ask Allah to make it easy and He Will surely Help you, no doubt. Allah is our Guide and our Helper. He is there for us when everyone else is not and it is impossible that a person in dire need calls upon Him and He doesn't respond to that person eventually as long as that person is patient. Islam is not nearly as hard as people think it is. It is living outside of Islam and away from the obedience of Allah that is excruciatingly painful and difficult.
May Allah Forgive us our sins, rectify for us our affairs and Grant us al-Jannah from His, Rahma, Generosity, and Compassion. Ameen