If you are feeling 'starved' you are either eating too few calories; have dropped too quickly; or you aren't eating a balanced, healthy diet with a good amount of healthy fats/ lean protein/ and good carbs (think wholegrains; fruit; veges)
It could also be that maybe you are weighing yourself too frequently and expecting to see sudden and/or regular drops. Weightloss doesn't work like that, and there are times that our bodies will increase in weight a little, and not because we have done anything wrong.
Given that you have indicated that your weight-loss goal is over 40kg, I strongly suspect that 1200-1300 calories is NOT enough. I was in my mid 50's at the time, and 5' 6" (shorter now LOL) didn't get anywhere near the recommended amount of exercise due to skeletal and fatigue issues, and my Registered Dietitian's weight-loss goal for me was far less. She put me on 1400 calories, which brought about a slow but steady weight-loss. By tweaking my diet a little I was able to find filling foods that worked well. (I was already eating a very healthy diet!) I had been slowly gaining on an average intake of 1650-1850 calories daily. I keep a spreadsheet which includes my weights (taken at my Dr's Medical Centre), calories; what exercise (type and amount) etc. I discovered that at the time 1600 calories I was able to maintain. More than that and I would very slowly gain weight. Less and I very slowly lost. Since having lost a lot of weight, I can now eat just on 1650 average per day to maintain, however I still eat as tho' I am in weight-loss mode, and have my special treat day slightly more regularly (once every 2-4 weeks.)
I either eat too little in my calorie allowance and end up binging or I don’t lose weight at all because I have upped my calories. Just curious if anyone has a weight loss ‘sweet spot’ calorie wise where you don’t feel starved but are losing weight. I’m in my 50’s and am noticing weight loss is slower, at one point I was eating 1200 to 1300 calories just to get some movement in the scale.