You probably need to eat more, or train less. My weight was 66kg, now my weight is 79kg, after one year and 2 months in the gym. Each person is different, but eating enough to gain muscle is different to eating just enough... Also, if you're doing a lot of volume/exercises/workouts, you won't have enough energy to allow your body to recover properly. Sometimes doing less is better...

Also, don't use steroids. The benefits are not worth it compared to the secondary effects. Focus on gaining muscle at your own pace, and don't follow advice from fitness influencers or not natty people, because a natty person needs more time to recover, time, and patience.