A bit lost in my journey

Hi, I don't really have people around me in a fitness journey so I was hoping to have your opinion bcs I am a bit lost.

I changed my diet in January and started to add more workout. Then I realise I should just workout with FB bcs I knew them already and had great result few years ago without changing the way I was eating.

I did FB abs FB booty I am more than half way into FB30 and results are great I lost 10 kgs my legs are strong I discovered how my arm muscles are supposed to look like. Well I don't have abs but they are shy. So I am really proud of the results so far and I love my body more and more. And I enjoy FB even when I am dying in front of their videos.

My issue is the food. I slowly changed portion sized in January specially carbs ( I was eating way too much). Now I am around 1800 kcal per day and it was ok.

Now it's been a couple of week where I don't know what to do. I don't think i am on a plateau bcs I still loose, just slower like 0.5 kgs in 2 weeks instead of 1 kgs and few millimeters insted of cms. Now that I lost 10 kgs I should reduce a little bit but lately after an intence HIIT workout I feel weak. I am not starving but I feel like I need more food. And I feel tired and started to take magnesium to help even if I sleep well and enough.

Is it possible that in the end I need more food even if I lost weight. That maybe bcs I have more muscles I need more fuel? I looked online but I still don't know if I should stick to my 1800 or eat more and hope I will not gain.

Sorry for the long post it really bother me, I don't want to give up but I want to make sure I am not going the wrong way.

Btw I am 1m69, 69kgs / 5.54" 152.11 lbs (if I am correct...)