If you are jelqing properly and make sure that you aren't doing it too much, then you should be getting better erections and gaining length and girth to a small but noticeable degree.
I would check your technique, the amount of pressure applied with your hands, and how often that you perform your routine. Chances are that you are applying too much force and or jelqing too often... are you grabbing the tip of your penis (pulling gently upward) with one hand and making an o.k. shape with your other and milking your cock upwards for repetitions of maybe 20 to 30 times no more than twice a day? You need to put more pressure on the top part of your penis than the bottom half, cause that's where the business end of your erection resides (more pressure with the thumb and less with the index finger... it's a slight imbalance, but noticeable).
Good Luck and make sure that you moisturize your cock with the lotion or cream of your choice and let it get plenty of rest.