Off to uni with girlfriend

Me (20) and my gf (18) have been together 3 years now and lived these 3 years on long distance relationship as we live in different countries. Our relationship is very serious as we spent everyday on skype and all our holidays(christmas and summers) together.

As I lost 2 years of education when I moved to the country she and I have now got into the same uni both doing science (maths and biology).

Because of the halls being 500-600 pounds a month each we decided to rent a house and finally live together after these 3 years of our relationship and also save a lot of money as a house will cost about 600-700 pounds to rent a month and by sharing money we can put a lot of what we were gonna pay for the halls in our pocket.

Everyone thought is saying that the worst idea of uni life is going to uni with a girlfriend and even worse staying with her in the same house. Now i usually dont listen to what people have to say about me as most of the times is just inaccurate but i hear this about uni vs gf a lot. Like all day long by different people and it has put me off a little bit.

We are very good together and never really had any problems, we had our ups and downs obviously but nothing major. I just waited for this so long it was like a dream for us but i dont want this to destroy our relationship and also our uni life.

But at the same time i feel like i cant really go back now even if i wanted to, i cant be like you know what i changed my mind and i am going to a different uni. Not that i want to but i heard and hear a lot lf negative comments about this and it has confused me and made me doubt it a lot.

Any thoughts or experiences?