If it is hard to go out then don't go to parents evening and another meeting about the bullying.
In all schools I have been involved in (4 children, lived in NE and SW, so a few schools) any parents who can't make parents evening or have more than a few minutes of things to discuss are able to make a separate appt on a different day to go over things.
If you are going to discuss the bullying at another time then just arrange that appointment with your son's teacher and say you can do parents evening stuff at the same time. This means you only have to do one outing - beneficial to you, and the teacher has a gap in their appointments. They can then try scheduling some one else in they couldn't fit in and had to see another day or they have a few minutes to catch up from previously overrun appointments. Most teachers in our primary would appreciate a few spare minutes just to grab a cup of coffee or catch up on over running, they are always pressured to get everyone seen but also to leave on time!
As for what you need to discuss. How about, between now and the teacher meeting, writing down what you need to say. This way you can make sure everything relevant is there and if you do get emotional you can refocus using the list. It is easy to forget/get lost off when emotional and miss things. You can even give the teacher your notes if needed.
On another note, ds3 is 11 and went up to secondary school in September. He was being stopped every so often by some yr 8 boys telling him he was some YouTuber with 2,000,000 followers blah, blah, blah. Surrounding him and holding him up, making him feel a bit intimidated etc. What might be called 'low level' bullying.
We gave him tips on trying to prevent it and said to tell us if it keeps happening so we could mention it to school.
His first meet the teacher (parents evening to meet just his form tutor) came up and when we went to book in on-line it was full. (27 appointments available for 30 children). Ds's form tutor sent a message home with him to say we could arrange another time to go in if we wanted. So we thought we'd e-mail and arrange a time.
On the Monday before meet the teacher ds came in and told us of further problems with the boys, resulting in him being late to tutor time and getting a 'ready to learn' warning. So we e-mailed his tutor, saying can we meet and there is also another matter to discuss. We arranged to see her on the Wednesday (one day after meet the tutor evening anyway) and had a relaxed meeting.
We did the progress report and how son was doing first, then got down to the other boys. She took it more seriously than we had, wrote down words like 'ds felt intimidated' etc. and also knew at least one of the boys (and wasn't surprised when his name came up). She said she would e-mail all the form tutors involved, the yr7 and 8 head and yr7 and 8 pastoral leaders and possibly other relevant (yr 8, deputy head) teachers if needed; various teachers would speak to the boys etc. etc.
She spoke to son about it, assured him they could sort it, told him he needed to feel safe at school rather then not feeling he couldn't go to certain areas when the other boys were there, that he should not be made to feel intimidated while at school etc. Later that day she sent us an update e-mail about who had been informed and it would be tackled with the boys over the next couple of school days.
She also checked with ds if it was ok to talk to the other boys. It would be obvious it was ds who had 'told on them' and he needed to know the boys could retaliate and escalate the bullying. Ds knows if that happens to go straight to a teacher and get it stopped. Thankfully we know the school will stamp it out, they have already sorted out problems for our older boys on the school bus from before we moved closer to school (they now walk), we were surprised as thought it would have been the bus drivers/companies responsibility, but school sorted it immediately.
Sorry to go on so long, but from this you can see that some bullying that is not as bad as what your ds is dealing with has been taken very seriously by his (secondary) school. Your school has to take this seriously, it is affecting your ds and you and it needs sorted.
If you can, find their bullying policy on-line and look for what the school say they should do. Ask them questions that reflect what they have said they need to do in their policy. E.g. What are you going to do to safeguard my son? If you do make notes of what to say to the teacher, add on any questions you'd like ro ask so you don't forget one, write down any responses from teacher too so you have a record. I know notes help me as I get very nervous when talking to people, especially if I've never met them before, this nervousness make me forgetful and I rely on notes to jog my memory.
This is not something school should do the minimum it needs to do with and then think it is sorted. It is something they should monitor and check isn't continuing. If they haven't done that then you definitely need to bring it to their attention and get something done about it.