Sport need some advice

[anatomie88]

Hi im new to the forum... im just after some advice because i feel stuck! i am not overweight but the past few months ive put on around 3kg.. i think i have damaged my metabolism because my calorie intake used to be very low and ive slowly upped it to approximately 1400 calories a day which is probably still low but it feels like enough for me. i do minimal cardio and lift weights 3 - 4 times a week. im not sure if the weight is muscle or fat because from what ive learned you have to eat a lot more calories than maintenance to build muscle. i would like to maintain the muscle i have and lose a bit of fat to get leaner but i am scared to decrease my calories any lower because that might do more damage but on what im eating now im not losing any weight either and im weighing pretty much all my food now and tracking calories! would it just be my metabolism has gone slow and how can i fix this to reach my goal? by the way i am 167cm and 123lbs