Keep coming back to certain weight

Hey everyone!

I have been on my fitness pal for some years now, on and off, and I have a problem because I keep coming back to a certain weight of about 60, 61 kilos. My height is about 168 cm (5"6 I think), and I could really lose some extra pounds. My goal weight is around 55 or 56 kilos.

I started counting calories again and see that with the exercise I do (40 minutes elliptical a day, plus I take the bike 5 days a week to school which is about 10 km a day) I have enough calories or I even have some calories left at the end of the day. (1500 calories, eating back those from exercise).

I don't eat so much at the beginning of the day, and the only thing that I find really hard to calculate is the amount of calories I eat at dinner, but I try to count them around 700. I eat very varied and most recipes and things don't appear on here, plus I never know how much grams I ate of what.

Could anyone give me some insight, is there anything I am doing wrong, anything you would recommend? I really just want to get rid of those extra kilos before summer and enjoy myself at the beach!