not to worry
every one stips bolts once in a while. take it to a local shop if you are really worried and ask them to get it out for you, see if you have a good independent in your area. make sure you pick up the extra bolt before going there. Then when the guy puts the new one on tell him not to crank it down so that you have to go back three months later. Also, try a search on strip or something like that, it comes up frequently and there are several manufacturers who make little gadgets to help with the fubar bolt. Craftsman at sears sells some, try adding one of those to your xmas list and see if it helps out. above all don't keep going out there with the vise grips to see if you can get it off, get the right tool or help.
1985 190e 2.3