Recently Reunited, Affecting My Sex Life

Hello, I'm brand new here. I hope this is the appropriate place to be posting this. After searching the forums for awhile, this seemed like the most fitting spot. Anyways, I was recently reunited with my birth mother and biological sister. It was an extremely fast process, which was a total shock and surprise to not only me, but also my A-Family, friends and girlfriend. My birth mother and sister are great people. I haven't been struggling at all trying to connect with them and begin a healthy relationship. I have, however, been coping with the stress of all of the situation in some peculiar ways. Recently, when my girlfriend and I start fooling around, I've had occasional trouble gaining, or maintaining, a good erection. The only other time this has ever happened to me is when I've had something HUGE on my mind. Before you ask, no, I haven't lost interest in my girlfriend. She is beautiful and incredibly sexy. I've searched the web looking for explanations and causes etc, because I'm concerned I may have early ED (erectile dysfunction). Keep in mind, I'm only 24 years old, it would be extremely rare for me to be affected by the physical problems that are often associated with ED. The reoccurring theme I see is stress and anxiety as main causes for "impotency". I'm also concerned because when my girlfriend and I begin making love, I don't have anything on my mind. In other words, I'm not thinking about all the stress I've been feeling, but it seems to prevent me from fully engaging. In conclusion, I'm not even sure why I posted on here, other than I know this is the most supportive spot on the internet relating to what I'm going through. Not sure what I'm looking or asking for. Also, this isn't the ONLY problem I've experienced, just the only one that has had a physical manifestation. Thanks for reading and, potentially, responding.