I have been involved in several relationships. Which involved being alone with girls, kissing, holding, hugging, and almost everything else but penetration. However, as you might imagine, during these moments one can not be sure whether I have had penetration or not, most likely not. It’s been several months since I have been with a girl, but that is maybe because having girls is not as convenient as before. I, indeed, feel guilty, regret that I have been in these relationships, don’t have intention to have “Haram” relationship anymore, and have performed repentance (tauba) several times. However, my problem now is I feel Allah (SW) is giving me almost everything I ask Him. I'm living a wonderful life, happy with my family members and have a very nice job, except I feel Allah (SW) is not giving me the wife I want. Whenever I find the one, my requests to marry her get rejected, although I always make “Dua” for Allah (SW) to give me the wife that will help me in this life and hereafter. I'm always making “sadaqah” to poor people and Islamic projects in order for Allah to forgive me. Do you think my “tauba” is not sufficient and Allah is still angry with me or it’s a matter time?
Please help me.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

It is a good thing to repent from relationships with alien girls and all that entails of forbidden things. Islam does not accept such relationships. Because, such relationships always lead to great mischief.

Know that Allah is merciful and accepts the repentance of His slaves. Allah says: "Say: "O 'Ibâdî (My slaves) who have transgressed against themselves (by committing evil deeds and sins)! Despair not of the Mercy of Allah, verily Allah forgives all sins. Truly, He is Oft-Forgiving, Most Merciful. (Az-Zumar 39:53)

So do not lose hope and be sincere in your repentance to Allah and never commit those sins again.

Since you repented to Allah, Allah blessed you by opening ways of provision and earnings to you.  So you should be grateful to Him. And the hardships and difficulties that you have in getting married are probably tests from Allah, so you have to be patient and choose a pious believing woman, and ask Allah to facilitate this matter for you.

Imam Muslim reported, in his Sahih that Shuaib, may Allah be pleased with him, narrated that the Prophet (Sallallahu Alaihi wa Sallam) said: "Astonishing are the matters of a Muslim."In fact all his matters are good, and this is for nobody else except for a Muslim. If something good happens to him and he is grateful, then this is good for him. And if something bad happens to him and he is patient, this is good for him as well."

Allah knows best.