Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Although the Fatihah is an essential part of the five daily prayers and cannot be dispensed with, in cases of necessity where the person for example is unable to recite the Fatihah because he/she is not a native Arabic speaker, the person is permitted to perform invocation of God (dhikr) instead of reciting the Fatihah.
Answering your question, Dar Al-Ifta Al-Misriyyah, states:
We would like to welcome you to the folds of Islam. One of the golden rules in Islam is that God the Almighty does not want to place hardships upon us and does not burden us with more than we are able to bear.
Although the Fatihah is an essential part of the five daily prayers and cannot be dispensed with, in cases of necessity where the person for example is unable to recite the Fatihah because he/she is not a native Arabic speaker, the person is permitted to perform invocation of God (dhikr) instead of reciting the Fatihah.
As for you inability to say the tashahhud, it suffices the person who is unable to say the tashahhud to say the testimony of faith (Ashhadu ana la illaha illa Allah wa ashhadu anna Muhammad ‘Abduhu wa rasuluh) and then he/she praises Prophet Muhammad by saying (Allahumma Salli ala sayedna Muhammad). Saying this would suffice you and render your prayers valid until you are able to recite the Fatihah and tashahhud in Arabic.
It was narrated that Abdullah ibn Abi Awfa said: A man came to the Prophet (peace and blessings be upon him) and said: “O Messenger of Allah, teach me something of the Quran that will suffice me, for I cannot read.” He said, “Say: Subhaan-Allaah wa’l-hamdu Lillaah wa la ilaha ill-Allah wa Allahu akbar wa la hawla wa la quwwata illa Billah (Glory be to Allah, praise be to Allah, there is no god except Allah and Allah is Most great, there is no god except Allah and there is no power and no strength except with Allah).” The man made a grabbing gesture with his hand (indicating that he had learned a lot) and said, “This is for my Lord, what is there for me?” He said, “Say: Allaahumma ighfir li warhamni wahdini warzuqni wa aafini (O Allah, forgive me, have mercy on me, guide me, and grant me provision and good health).” He made another grabbing gesture with his other hand and stood up.
The renowned Hanbali scholar Ibn Qudamah said:
It may be sufficient for him to say alhamdu-Lillaah (praise be to Allah), laa ilaaha ill-Allah (there is no god but Allah) and Allahu akbar (Allah is most great), because the Prophet (peace and blessings of Allaah be upon him) said: “Whatever you know of Quran, recite it, otherwise praise Allah, proclaim His Oneness and magnify Him.” (Abu Dawud)
The difficulty that you find in reciting Quran will increase your good deeds and rewards. It was narrated that Lady Aishah (may Allah be pleased with her) said: The Messenger of Allah (peace and blessings of Allah be upon him) said: “The one who is skilled in reciting Quran will be with the noble and obedient scribes (i.e., the angels) and the one who reads the Quran and struggles with it because it is difficult for him will have two rewards.” (Muslim)
The erudite Imam Al-Nawawi (may Allah have mercy on him) said:
The one who struggles with it is the one who is hesitant in his recitation because he is not able to memorize it well. He will have two rewards: the reward for reciting it and the reward for his efforts in reciting it.
Almighty Allah knows best.
Source: http://www.dar-alifta.org/Foreign/ViewFatwa.aspx?ID=8030