Lately as I have read some Hadith of the Prophet(s) and read who the hypocrite is and his characteristics, I feel as if I posses some of these characteristics. I don't feel the sincerity that I used to feel in my heart just a few years ago. I don't pray all the prayers if I am alone, but if someone is there and tells me to pray I do. I feel that I'm doing wrong and I feel like a bad Muslimah. I really want to change myself, to be a sincerely pious Muslimah. Is there any Dua' I can say to put sincere piety back into my heart? If there isn't, what can I do because I hate myself so much for how I'm acting and my ways?

Praise be to Allah, the Lord of the World; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
The following things must be clear in your mind:
First, you mentioned that you fail to pray some of the obligatory prayers if you are alone. But you pray when another person reminds you of praying. Know that giving up voluntarily any of the obligatory prayers is a great catastrophe, a great danger and a major sin. Allah warned those who do not pray because of laziness. Allah Says (interpretation of meaning): {So woe unto those performers of Salât (prayers) (hypocrites), Who delay their Salât (prayer) from their stated fixed times,}[107:4-5].
Those who are meant in this verse are those who delay the prayers from their fixed time. The punishment becomes greater if the person not only delays praying at a given time but fails to pray at all. So, you should repent from this grave sin and never miss performing any obligatory prayer.
Second, we advise you to befriend only good pious people. In fact, the good company will remind you of performing good deeds and sticking to these good deeds. Also, try to know the times of Adhan (call to prayer) and anytime it is called, pray before you forget to do so. The Prophet was once asked about the best deed one could do. He replied: "(Performing) the prayer in its fixed time", i.e. the prayer in the early part of its fixed time.
Third, know that the prayer is the second most important pillar of Islam. It comes just after the Shahada (witnessing that nothing deserves to be worshipped but Allah and that Muhammad (Peace and blessing be upon him) is His messenger). The prayer is also the first thing Allah will ask the servant about on the Day of Judgement. The Prophet said: "The first thing the servant will be judged for on the Day of Judgement is the prayer. If the prayer is good and valid, the person is then considered a successful winner but if the prayer is invalid he is then a disappointed loser". [Al Tirmizi, Al Nasai and Abu Dawood]
So, if you feel the greatness of the prayer in your heart you will do your best not to miss to perform any prayer in its fixed time. Always have in mind this verse. Allah Says (interpretation of meaning): {Guard strictly (five obligatory) As­Salawât (the prayers) especially the middle Salât (i.e. the best prayer ­ 'Asr). And stand before Allâh with obedience [and do not speak to others during the Salât (prayers)].}[2:238]
Fourth, being obedient to Allah, enjoining the good and avoiding the bad is the most important means to keep performing prayers in their fixed times. In fact; one should keep away from bad and harmful environment as the bad deeds darken the heart, makes it harsh and ill. So, if you are really willing to be steadfast, you should enjoin the good and avoid the bad.
Fifth, one should act as Allah Says (interpretation of meaning): {Surely, Allah wastes not the reward of the Muhsinun}[9:120]. Allah also Says (interpretation of meaning): {As for those who strive hard in Us (Our Cause), We will surely guide them to Our Paths (i.e. Allah's Religion - Islamic Monotheism). And verily, Allah is with the Muhsinun (good doers).}[29:69]
Sixth, there is no Dua' (supplication) specially designed for helping one perform the prayers in their fixed times. But one could say: "O! Allah bestow on me the love of the prayer and make me perform it as You prescribed". "O! Allah help me to supplicate You, remember You, thank You and worship You in the best way".
Finally, we advise you to read as much Qur'an as you can, to supplicate Allah to forgive you and never miss the prayers, no matter how busy you are.
We ask Allah to guide you and us to the right path. Allah knows best.