1999 Ford Explorer not reverse

Transmission problem
1999 Ford Explorer 6 cyl Wheel Drive Type unknown Automatic 125000 miles

2 weeks ago I lost my reverse and the vehicle is still driving foward fine I cant hear any noise or anything different in the car just that the reverse doesnt work also in the instance that the transmission stopped working it burnt two fuses do you think this is a problem internally in the transmission or it could be an electronic problem? If this is a electronic problem what components have to be replaced please give me names of the components and if it is possible for me to do the replacements? And if it is an internal problem what could it be? Thank you I hope you can help me