Quote - "I can't afford a gym membership just yet, and in fact am thinking of just purchasing a home bench at the end of September. So right now, my excercise is, curls, tricep extensions, overhead dumbell lifts, pushups and situps."
If this is all you are going to do, why bother? You need to work your legs, chest and back in addition to the body parts you are now working. If you want consistant gains in strength/size, you must be consistant with your diet and your workouts. Instead of spending you money on supplements, buy some wts. A little at a time if you are strapped for cash (check for used stuff at garage sales, the paper, etc.). You do not really mention your diet. Is it in order? Lots of lean protien, minimal simple carbs, etc.
You say you have little to no patience. Therefore, (IMO) you will get little to no gains from your approach.
Read the stickies at the top and get a better understanding of what is needed to be done to get more size and strength.