(((Nthnzmmr))) First let me say how sorry I am that you are going thru this. It's tough, I know....
I am assuming you don't have a signed open adoption agreement but if you do... It may be legally enforceable.
I think the most important thing here is for you to take care of yourself. Remember, you want your son to be proud of you and you must be a good influence in his life. If you don't feel like doing this for yourself today, do it for him... OK? I am glad you're seeking some counseling. You may want to call a few agencies in the area and ask if they know of any active support groups for birthparents in your area. I think talking things out face to face with people who have been in your position will be just as helpful (if not more) then a regular councilor. Adoption is a unique type of grief for sure. Also, stay here and post.... You will be surprised at how many folks here have felt the same thing you are feeling at one time or another. This place is a great support in itself.
Also focus on getting your head back around school. Summer is almost here... You can make it. This will get better... I promise. You are not failing anything right now... You are grieving so don't beat yourself up. This isn't who you are... it's what you are feeling like today... Does that make sense?
Now, as far as the open adoption (OA) goes, I have no experience as a birthparent. I absolutely think there are things you can do to open up communication again but I will wait to offer some suggestions. Hopefully those who are living OA will chime in - they are the experts
You will get thru this I promise... Hang in there...