If you have a straight bench press bar at home, your lifts are not limited at all.
Bar- deadlifts, squats, bent over rows, bench press, good mornings, Stiff legged deadlifts, power cleans, snatches, overhead squats, front squats
Curl bar- skull crushers, bicep curls
You have no excuses, the only good exercises you cant do are dips and pull ups, but you can do push ups and all ab work without equipment.
The key isnt time, its intensity, you must be FOCUSED for that half hour you work out, I am always in a heavy sweat when I am done.
you also dont need 2 grams of protein per pound, id say just aim for 155 grams a day, dont worry if its lower.
ps get a hair cut.