Hi,
Please stop these pranayama exercises immediately as you are doing it without guidance and because you are so new to yoga you may actually damage your nervous system. Pranayama is really something that you should do with a teacher and I want to emphasize that you should find one or a more advanced yogi who can help you in future with this. I will try my best to guide you. Another point, you must count, that is the only way to find your breath that will be comfortable for you, but this you can do later. I myself introduce alternate nostril breathing only to my beginners classes after about 4-6 months of yoga practice and then I gradually increase the frequency etc.
What is important in the beginning of yoga is to learn correct abdominal breathing. I spent the first six months doing only this with beginners as this prepares you for the more advanced pranayamas later.
Abdominal breathing minimise the action in the rib cage and enhance the action of your diaphragm. Most people lost the ability to correctly breath with their diaphragm and use the rib cage in nearly 100% of breathing. Once abdominal breathing is corrected you will experience greater health, more energy and the other pranayamas will be easier.
How to do Abdominal breathing:
Lie is dead corpse pose (shavasana) and relax the whole body. Observe normal spontaneous breathing without controlling the breath, just breath and watch where it goes. No counting here. Do this for about a minute or so. Now, place your right hand on your abdomen, just above the navel and your left hand on the centre of your chest. Which hand is moving up the most? In normal (uncorrected) breathing your left hand should rise more than your right on the abdomen.
Now, start to shift the breathing into your abdomen, don’t force it, do it gently, your right hand should rise now more than your left. Try not to expand your shoulders and chest, but rather your stomach area. Exhale slowly and feel how the right hand falls. The left hand on your chest should move very little when you breath in to the abdomen.
Do this only for a few rounds about 5-7. Relax and practice this constantly for about 4-6 months. You may gradually increase the frequency over the next few months until this type of breathing becomes second nature for you. Then you can attempt the more advanced pranayama, but only under gauidance from an experience teacher or yogi. This is important.
Hope this help. Please remember this is only my view, this was how I was taught and someone else might actually offer something else, you must find your own middle path in what is offered.
Good Luck.