I hope someone can give me a bit of advice here please.

Every so often my ca\r will not go into 1st and reverse gear while the engine is running, I have to turn engine off, put the car in gear and off I go, the rest of teh gears are a bit of a struggle. Clutch peddle is down to the floor. If I try to put it in reverse while engine is running it crunches like crazy, but 1st gear...not a chance will it go in

Being a female driver (hold off on all the comments haha) I'm often told a load of rubbish by garages..Last garage told me it was a knackered gear box so will need a new one and a clutch to go with it or I probably had air in my clutch cable and to go home and rest a stick down on it all night to release the air...I do have enough intellegence to know my car doesn't have a clutch cable lol .. it's fluid...which is full. I have a gut feeling its not the gear box, as had one of those go before

The car doens't do it all the time, it last for a day or 2 then is back to nomal with no problems, just when I start to relax about it it starts again.

can anyone give me some idea please on what you think it may be and a ROUGH cost

Thank you