Leaking on the T connection on the flush line

The T connection on the flush line started massively leaking. The T was replaced with a factory hose going the full length from manifold to fire wall connection. All seemed good until one week later.

Full tank of gas put in two days prior to the following and I drove fifteen miles to and from work that day with no clue of the trouble outlined below.

Vehicle started shuttering and grinding like a train. Smelled first of antifreeze then more like rotten eggs. There was a small amount of fog on the driver window.

Not over heating, not leaking. But the fluid in the neck of the radiator is way over filled and continues this trend even after spillage from checking it. Holding tank is maintaining.

Got home with check engine light going from solid to flashing and no strength in the foot pedal and would not smooth out It continued the wreaking smell. Daughter followed me home for the two mile terrifying drive and could smell it the whole time and no smoke.

No overheating, no smoke, no leaking on the ground but some antifreeze in the support rail left to right. Added a quart of oil, could see what looked like antifreeze laying on the oil in the crankcase but a slight green tint.

The gallon and a half used when the hose was fixed a week ago was orange.

Easy chair mechanics say: gasket, heater core, radiator, 02 sensors, bleed valve and of course catalytic converter. If I do all this it will cost more than this very reliable car. Please direct me? I don't think I can get it to a mechanic without driving it or an expensive tow. Disabled old lady.