Clanking engine while in gear

Loud clanking sound while in gear with very minimal movement from vehicle. In park the car emits a very low clicking. Now what I did wrong. So I had a radiator leak that I procrastinated on and did the fill up method every few days until I forgot and overheated while working not once but several times over the next two days, and I did refill to get me back on the road. Next day while working I was driving and the pressure while driving went down and the loud clanking sound started like the engine was going to fall out of the car so I pulled over and got it towed home. Thank you for any help.