I am 21 and plan to marry my 19-year-old fiancée in two years’ time.
We have great love for each other, which arouses equally great passions of love and affection. When we met after a three-month separation we were so excited that we could not stop ourselves from embracing and hugging and kissing each other.
We fear Allah and do not know what to do. Our financial situation is such that we cannot marry for another two years, we live in a Pakistani Sunni society in which fixed-term marriage – mut’a – is disapproved, but Allah knows we also cannot control ourselves. Please advise me how we may avoid sin.

To avoid sin do not, under any circumstances, be alone together. Your actions of hugging and kissing were sinful acts for which both of you should repent.
There are two aspects to consider.

1. Islamic rulings.
As far as this is concerned, it is not permissible for a boy and girl to kiss and hug prior to marriage. Planning and being prepared to marry in two years’ time is no excuse.
The appropriate solution, which accords with Shari’ah, is to marry in the presence of both sets of parents, and to hold a public wedding ceremony two years later when you can afford that.

2. The society in which you live.
The only thing that they need to know is that you are engaged. You are not required to expose your private life to all around you.