Discouraged

My partner and I recently began having sex after being together for almost three years. Since we got engaged in March, we have looked forward to this moment even more than ever before. When we “messed around” before full blown sex, I always finished and felt satisfied. But now...I’m really struggling. Lately sex has been ending in tears because I feel so blocked and discouraged. Im not feeling pain, I just feel....nothing. I’m not exactly asking for advice, as much as encouragement from this community that it will get better and we will tap into that “wow” feeling. Anyone else experience this block? Am I crazy? Should I be (God forbid) worried?