I really need a good workout regiment to lose weight and try building mass?

Weight loss and muscle building are two different things.

Weight loss depends on eating few calories than you burn in a day. Never try to lose more than 2 pounds a week.

Muscle building is from weight training.

As for appetite ...

eat ONLY 600 pounds less a day than your current maintenance-level of calories is. And one day a week, go OFF your diet (so your body won't lower its metabolism in response to a food-shortage).

Eat 5 times a day, and always have a bit of protein in there.

Make one of your meals a high-protein powder in milk, to help build muscle.

I suppose you can do things like push-ups and squats, using your body weight as your "weights" ... but be careful and do the squats properly so you don't damage your knees.

And you could use water bottles (1 gallon of water = 10 pounds) for a MILD workout for your arms.

But without weights, you aren't going to build much muscle. Is there is YMCA with a gym and a pay-as-you-go plan?

So, to stop eating too much (well this is what I do) go to sleep really, really late (like 3-4am) so you can wake up super duper late. Meaning you won t have much time to eat before your family go to sleep/bed and won t want to be disturbed.

Take your weight and multiply it by 10... eat that many calories each day, and chose simple ingredients like veggies, lean meats, fruits, and legumes. Fruit and vegetable skins are a pain for your stomach to digest, so you feel fuller longer if you consume them along with the rest. Also drink a lot of water.

Split your time at the gym between cardio and weight lifting. Google up a simple 5x5 program and stick to it; hit the gym at least 4 times a week. Begin each morning with a simple aerobic routine; you can find plenty of YouTube..

3 months is too short a time frame for significant muscle gains. And I would strongly advise you to leave your house and tame your anxiety. It can be done.