Dude I feel for you brother. Some women are very apperance oriented when it comes to the penis they play with. Veins to some women are a turn off. Some women prefer a penis that is cut and other women prefer a penis that is not cut .
Women can have a similar reaction to veins resulting from body building. I dated a women that was absolutely revolted by those men who work out a ton and get huge veins. She liked a good build on a guy and nice muscles, but not to the point there are veins popping out. So you have lots of small veins as well as a few big ones? It maybe that you have some smaller capillaries that have become damaged and it’s causing that appearane. If that is the case after a layoff they should go away and perhaps you can start again with a less streneous work out. I would say that getting an extra inch or so may just not be worth it if it’s going to give you an appearance your girlfriend does not care for. Particularly if you have a partner that is very oral and satisfied with your penis size already. You don’t want to miss out on good head because she is put off by the veins. Remember there are always toys and other things you can get to pleasure her with greater size while keeping your penis looking ‘pretty’ for her.
Now perhaps it’s possible to still do stretching and make some progress there without bringing out the veins. Maybe try laying off for a while and seee where you end up and then take a picture. Do light stretching and after a few weeks compare. I would suspect jelqing would be more likely to bring out veins that stretching but it’s only a theory. Maybe someone with more experience in this could chime in on how you could still do PE but at least reduce the possiblity of veins. People are different and some for example have a ton of veins in their legs that are less that appealing.
Good luck and please let us know if your veins get better after you stop for a while.