I do not have trouble with coffee but I am not a big coffee drinker. Whether it is your anxiety or your GERD, it may be wise of you to just try giving up anything with caffeine in it.
Try to stay out of the 'what if?" anxiety lane and stay in the "I am OK" lane. The more you over think "what" may be causing your symptoms the more anxious you become.
Know we are here for you and have great faith that you will be OK. Stick with us as we are here to support and share with you.