Welcome to HCM,
You have started on right line please keep it up,first letme tell you or may be you know it that your ideal weight would be near 70 kg so you need to lose 10 kg more but it is possible you have to make realistic goal like keep a target of 500gm to 1 Kg every month.
In diet take a balanced diet of proteins
,fat and carbohydrates to make 2000K cal/24 hours.
You take non veg then take egg white not yellow,consume lean meat in limited quantity.
take fresh fruits and lot of green vegetables and salads.drink lot of water.
Break fast is must and you can take a little every 2 -3 hours and please do not crash diet
as it is harmful.
On other end keep moderate exercise regularly and reward yourself with some thing and keep motivation so that you do not stop your efforts in between.
It is possible take help of dietician and personal gym trainer and do not take any supplements or steroid
for making muscles.