Hey friend, i used to be in your skin. I am 173cm tall / 5"8 (i believe) also male and after my cut i weighed 60kg. I used to be quite chubby with 82kg and after losing it all i felt great and confident. So naturally like you i was very hesitant about eating more and gaining weight, i tried training for a few more months but ultimately gave it up because i was very happy with my new skinny self and also made no progress in the gym.

Fast forward 2 years and i gained 10kg again, putting me at 70kg. I started to get unhappier and decided it was time to cut again. I sucessfully put myself to 60kg again after a couple months of cutting. Being at 60kg wasnt enough for me then though, i decided to enter the gym once again. This was exactly one year ago and in all this time i have been on a slow bulk. I now weigh around 74kg (which means i gained around 14kg in those 12 months) and am extremely happy. I have gained a lot of muscle mass and also quite a bit of fat, but it doesnt bother me. The thing is 14kg of muscle + fat gain looks so drastically different from 14kg of pure fat gain. Here is a pic of me now: Sorry for the small picture I now simply look "beefier", you can see i am not thin or skinny, but you can also see i have musclemass.

You see there is nothing to fear about. I learned that loosing weight (especially small amounts like 10kg) are easy short time fixes. I mean 3-4 months of cutting? You can do that shit anytime you want, thats not too much effort. Imagine the worst case scenario for you: you gain 0 musclemass and only fat. Ultimately how bad can that be? You can just take a couple months and cut right back down if youre unhappy.

If i were you i would start concentrating on the resistance training and dont worry about the scale too much.