Salamualaikum wa ramatullahi wa barakathu!
I've met a guy, who's also muslim online. So we started chatting for 3 years until today. First of all, we had plans marrying in 5 years ( from today on, that would be 2 more years). We started Meeting up, but never ever have we started commiting Zina. Ee just went out in public places, to go in a walk, grab some food and Talk, though now i got to know, that is forbidden. Nevertheless my father isn't aware of him now, because I haven't told him Yet. The season for that is, that he lives in the north and I'm from the South. We are still attending university and won't be capable to graduate until in 2 years. Somehow I started Feeling uncomfortable meeting up with him, so i stopped it, after i got to know, that its haram. Still I'm Feeling bad chatting with him behind my fathers back and that even if I would tell my father now, the fact, that the marriage won't be yet, but in 2 years also gives me a Bad Feeling. I've got the Feeling, that it is wrong, according to islamic law. But marrying in the current Situation would'nt be an option for me, because I can only study my subject here. So I told him that and he was okay with no more meeting up. But he wants to continue chatting with me in a group with my sister via whatsapp or through an islamic app, in which someone would watch over the chat, so that there would be no forbidden Talk. Also he does not want to marry me until in 2 years, when he has finished his doctorade. But he is a sincere and generous person, who prays, fasts and so on.What should I do? Shall I break up this relationship or continue, and if so, how?
Baraka allahu feek!

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, is His slave and Messenger.

You did the right thing by cutting off communication with this young man and stopping chatting with him; this act is forbidden and one of the causes of evil and corruption. Having lovers (boyfriends) is one of the evil morals of the pre-Islamic period that Islam deems forbidden, as Allah, The Exalted, Says (what means): {…[They should be] chaste, neither [of] those who commit unlawful intercourse randomly nor those who take [secret] lovers…} [Quran 4:25]

However, merely cutting off communication with this man does not constitute a valid repentance as per the Sharee‘ah until you fulfill all the conditions of repentance; namely, regretting the sin and resolving never to commit it again in the future. You should conceal your faults and not tell your father or others of what you did. It is incumbent on a Muslim to conceal his sins. Abu Hurayrah narrated that the Prophet said: “All my nation are forgiven (for their sins) except those who commit sins openly (or disclose their sins to people). An example of such disclosure is that a person commits a sin at night, and though Allah screened it from people, he comes in the morning, and says, ‘O so-and-so, I did such-and-such (evil) deed last night.’ Though he spent his night screened by his Lord (none knowing about his sin), yet in the morning he removes the screen of Allah from himself!” [Al-Bukhari and Muslim]

There is nothing wrong with you both joining a public group on social media in which everyone can see the posts shared by others, and you should beware of any private chatting between you because it may lead to Fitnah (temptations).

We would like to point out that you should hasten to marriage as much as possible and facilitate it; it is the best advice given to those who are in love, as was authentically reported on the authority of the Prophet : “There is nothing like marriage for two who love one another.” [Ibn Maajah]

Allah Knows best.