Assalam O Alaikum,
My dear dear sister sounds like my dear dear brother Idris Tawfiq, Reverted British Catholic Priest, who I guess also knew in his heart that he was ready to say Shahadah and accept Allah as one and only God. He infact used to fast in the month of Ramadan to encourage his Muslim students, even though he wasn’t a Muslim. Once he met Yusuf Islam, the former pop singer-Cat Stevens, and asked 'What do you actually do to become a Muslim?’ He answered that a Muslim should believe in one God, pray five times a day and fast during Ramadan. He interrupted him saying that he believed all this and had even fasted during Ramadan. So brother Yusuf asked, ‘What are you waiting for? What is holding you back?’ He said, ‘No, I don’t intend to convert.’ “At that moment the call to prayer was made and everyone got ready and stood in lines to pray. He sat at the back, and cried and cried. Then he said to himself, ‘Who am I trying to fool?’ After they ended their prayers, he headed to Yusuf Islam, asking him to teach him the words by which he announce his Shahadah. After understanding its meanings, He recited after him in Arabic that there is no God but Allah and that Muhammad is the Messenger of Allah,” Since then He is working for Islam, may Allah bless him in his work.
May I ask my dear sister the same question? When you know that Islam is the right religion for you than what is it that holding you back? also the fact that you are not converting to Islam, no one do, people return to Islam because we Muslims believe that Islam is the natural religion of mankind, which has existed since the beginning of time. All people are born Muslim.
My brotherly advice to you is that instead of waiting for the time when you know that you can commit your life 100% to Islam is not a right approach. Say Shahada now and try to practice the basic fundamentals of Islam but there is no rush in this. You may ask why we advice you to say Shahada now? Sister, we born as a Muslim we should die as a Muslim. As Allah says in the Holy Quran [3:19], "The only religion accepted to Him is Islam."
We don´t know what the future holds for us.
I am really happy that you have started learning arabic which indeed is really important, Quran has revealed in Arabic and in order to understand its real message one must know the language with its grammatical influence. I myself intend to do the same, soon Insha Allah.
Masha Allah, your fear that you will never be able to learn enough about Islam shows how much Taqwa(piety/heed/God-fearing) you already have. Indeed there is alot to be learn, a good Muslim can never claim that he have enough knowledge of Islam and don't need to have more. We are student and will always be student, keen to learn more.
You don't have to make your Shahada public if you are not ready to face your family and others who you fear will make your life difficult for you, as it was the advice of Prophet Muhammad(pbuh) to his companions at the early years of His Da´wah (Propagation) who had the same fear like you, even worst I should say. Make it public when you feel you are ready.
You will have to show patience no matter how much pressure your family force on you neither you have to feel any burdon or sin if they gets angry with you for being a Muslim. Infact you will have to show them the good example of a true Muslim, who treats his parents with kindness and respect, be they Muslims or non-Muslims. As mistreatment of parents is the Second major sin in Islam. You will have to explain them the beautiful teachings of Islam and will have to convince them with good example and behavior that it would be good for them to accept Islam. As Quran says, "O ye who believe! Save yourselves and your families from the Hell fire." They will have to see major change in your personality after embracing Islam, meaning what change Islam has brought in you?
Your past record/mistakes will become completely clean from the moment you will say Shahada. Then, the reward or punishment counter will starts running, you will be rewarded for the good you do and punished for the bad.
Indeed race shouldn´t be a barrier and you don´t have to feel odd being a white girl in arabs. As Prophet(pbuh) once said In another hadith, he (peace and blessings be upon him) said: "Allah does not look at your images or your colors but He looks at your hearts (intentions) and your deeds. Creatures are the dependants of Allah and the closest among them to Allah are indeed the most useful to His dependants."
Sister, you already are very welcome in Muslim community, TURNTOISALM, don´t you? same will happen,Insha Allah, once you will inform your intention to Muslims where you live and ask them to teach you more about Islam. WE MUSLIMS ARE VERY KIND WARM AND WELCOMING PEOPLE
. Your wish of having a big Muslim family is not a wish anymore, you already have a family now and I am one of your brother, ready to assist his sister any time she likes.
Wassalam
Brother Farooq
said, 
