[Cookiemonster]

Ya if your below grade that is a problem.

If you want to build the wall up I would suggest the following.

Drop the grade next to the house (have to excavate it out some to get access to the exsisting footing) remove your lower siding and put up your forms (2x12 or some 3/4 ply will work).

Just make darn sure that any crumbling or questionable concrete on the exsisting wall is removed first. Then go to town with your epoxy & concrete. I would throw in some # 4 rebar tying it into the exsisting footing. Be aware that you will need to support whatever that 6x6 is so it can be cut to go down onto the new section of wall.

Once cured I would remove the forms and trowel in a grout on the outside where the new & old conrete meet. Seal the outside concrete with a waterproof sealer, & drop in a french drain to carry away any excess water. Just don't forget to properly flash it all off too.

Good luck