I had one in both my births.
The first was an induction for reduced movements with a badly positioned baby, and ended up in an emergency C-section.
The second was an easy VBAC. I had the epidural at about 3cm dilated just as I was getting into active labour, then lay down and had a nap, and when the doctor came to examine me an hour and a half later I was almost fully dilated and ready to push. The anaesthetist made the initial dosage quite low at my request because I wanted to stay mobile but I dilated so fast after having the epidural I didn't have time to walk around or anything. It had more or less worn off by the time I came to push which was good because I wanted to be able to feel what I was doing. The pushing was hard work and a bit scary but for me not really any more painful than doing a particularly big poo when you are constipated. It stung a bit, yes, but it was really not that bad compared to the contractions before I had the epidural.
Regarding what this midwife told you, there are a couple of things you need to bear in mind. Firstly, in the UK, a lot of maternity units and in particular a lot of midwives are very anti epidural. There is a belief that the best way to give birth is with no pain relief other than a bit of gas and air. This belief is entirely cultural. There are other countries where the cultural belief is that it is completely unnecessary for a woman to suffer potentially agonising pain during childbirth when safe and effective pain relief is available, and the vast majority of women have an epidural, regardless of how their labour is progressing. I live in one of those countries, and my general impression is that there are a lot fewer women who seem traumatised by their experience of giving birth. (There is also a higher birth rate, although that might have more to do with the fact that having three or more children is incentivised through the tax system.)
The other thing to bear in mind is that any statistics which seem to show a correlation between epidural use and birth complications are inherently unreliable if they are from the UK. The reason for this is quite simple. In the UK it tends to be women who are having long and difficult labours, or women who are being induced with syntocinon, who have epidurals. Women having quick and "easy" labours generally just have gas and air. In France, where I live, most women have an epidural just because they want one even if they are having a quick and straightforward labour, like I did, and here there does not appear to be any correlation whatsoever between epidural use and emergency C-sections, instrumental deliveries or other unwanted outcomes. The rate of emergency C-sections is lower here and the rate of instrumental delivery is about on a par with the UK.
You do need to stay still while the needle is being placed but it doesn't take long and they will try to do it between contractions. You aren't in any pain between contractions so the only time this is a problem is if your contractions are too close together.
The epidural doesn't affect the baby in any way, that's a load of nonsense.
If you want an epidural I would advise getting it fairly early on. I got mine at 3cm dilated which was just at the moment my contractions went from manageable to unpleasant. I got it within about half an hour of asking for it, which was just as well because my labour progressed very quickly after that. If I'd had to wait two hours it would have been too late because I would have been fully dilated and ready to push. I think it is generally a good idea to wait until things are properly under way (i.e. you are in active labour) because it reduces the risk of the epidural slowing things down. But if you're going to have an epidural it doesn't make sense to labour for hours and hours and only get it when you're already exhausted. An early epidural allows you to conserve your energy and morale for the second stage of labour, which will improve your chances of having an unassisted delivery.
I also recommend keeping the dose quite low so you can still move around and still feel something. I could still feel the contractions after mine but it really took the edge off the pain. I felt really calm and in control. I could have got up, leaned against the bed, changed positions, sat on a birthing ball or even walked around a bit. I just didn't have time because in the end my cervix dilated really quickly while I was lying down having a rest. All the stuff about staying mobile and letting gravity help your baby come out sounds like common sense, but just to reassure you, you don't have to be standing up and twerking for your baby to come out. Plenty of babies are born in a perfectly straightforward manner to mothers who lie on a bed the whole time.
The choice is yours, OP. But for me it was definitely the right choice and I would do the same again if I ever had another child.