Know you can't eat sweets and chocolate, but in a morning i have sugar in my tea and porridge. is this okay?

Limit sugars!: All thing in moderation including sugar.You did not say how much you use. In general it is a good habit to learn to reduce the use of sugar in your diet. Natural sweetners, such as stevia, are on option. Use them sparingly as the more sweets you eat the more you tend to crave them. Do finish your meal with a healthy glass of water to help neutralize the acids bacteria produce from digesting sugar.