Congratulations on the weight loss, that's an amazing amount to have lost. Well done!
I'm not that clued up about gym stuff and there are others who are way more knowledgeable who I'm sure will reply.
There are ways to build muscle without the gym or any expensive equipment. Squats - I use a broom handle to keep balanced. Lifting/carrying heavy household objects. Free weight exercises, again using household objects.
- my brother is an extreme sportsman and he has a tractor tyre in the garden which he pounds away at with a large sledge hammer. He also goes running up mountains with my ten year old nephew on his back......