Bolting and panicy behaviour

Question
Hello, I have had my first pony- a 7 year old welsh gelding for about two and a half years now(5 when I bought him). He's a lovely pony, an excellent hack, good in the school and has done well in many basic dressage tests.(I ride 3 times in winter, 5-6 in summer).However last January he unexpectently bolted with me. Due to this being so out of character, we got his back/teeth/tack checked, resulting in his saddle being too small. After replacing it with a correctly fitting saddle, regular lunging I eventually bought him into work. Despite,seeming to be back to himself,he bolted 2-3 times again despite having frequent training from my riding teacher.
Just a few weeks ago,he'd been going well throughout the summer,I went to mount & as I did so,he ran off in a panic - half mounted I got thrown off.The next day,my riding teacher mounted and although tense he did not react.Thinking this was a one off spook,I remounted the next week,my mum holding him,again in a blind panic,he bolted throwing both me and her to the ground.I have now lost my confidence,he is fine when ridden by my riding teacher,so we know this behaviour isn't pain related.She now feels I can get back on,but I am very nervous,and afraid he will sense this. I would appreciate your help and suggestions,as now the only option seems to sell him.
Thank you very much.

Answer
Hi Joanna,
            The best advice I can give you is to sell your pony and find a horse that you are more comfortable with. If you do want to keep him you might want to see if you could find a horse that you could free lease while your pony's issues are worked on.

Lisa