Miscarriage and it was my fault!

I found out that I was pregnant at about 5 weeks. It was unplanned but when I found out I was ecstatic! I scheduled my first OB visit but was completely unaware of anything about pregnancy. I vaguely remember that hot tubs were a bad idea but I live in an area with beautiful natural hot springs. Before my OB appointment my boyfriend and I took a trip to one of these hot springs. I sat in it, cooking myself for about 45 min. It wasn't until after I miscarried that I realized what I had done to my baby. At 7 weeks there was no heartbeat at my Dr. Appointment. I cannot believe I was so stupid! Now I've been TTC for 6 months and nothing. I'm devastated and feeling unbelievably guilty that I caused my unborn child's death. Anyone who is pregnant after miscarriage? Any advice or if you just want to reiterate how foolish I was... It kills me inside!