Am I making the right decision?

A bit of a warning, this is going to be a long post.

So I had no idea what I wanted to do in life until time came to apply to university and I couldn't decide what to study in the future. After doing some research, I decided Medicine was for me, however, I couldn't apply because my grades weren't high enough and I didn't have enough experience, so I worked really hard to get my A levels and work experience, took a gap year during which I applied to medical school. I started my gap year full of hope and plans, however, it took a down turn, I got really tired and annoyed by my part time job, the disappointing medicine rejections started to come through, I got stressed preparing for the only one interview I had gotten, to perform to my best ability which resulted in me being put "on hold" for 2 months and then being rejected towards the end of the cycle. I started having problems at home and being without friends left me frustrated and angry. I put on a lot of weight as I started binging on food and basically this year turned in to a complete misery. However, I have an offer for my back up choice which is optometry and I would really like to go to university, meet new people, make friends and get involved in the whole social/drinking culture. However, medicine is still what I would really want to do but the thought of going through the application process again scares me.

I really hate staying under my parents roof and want to move out ASAP.
If I did take another gap year to re-apply, I would start uni at 20 which is a bit late and I feel I would miss out on all the first year social scene and I would be older than everyone else.

Also thinking about life as an overall picture, I'm not sure if Medicine would make me truly happy. I value relationships, love, people and extra time for myself where I like to relax and explore the world. I know this sounds really strange but you know when your in love with someone and the only thing you care about is the person your with and everything else basically just disappears and doesn't matter anymore. If I was to do medicine, I believe this part of my life would supersede my medical career, therefore I may not be prepared to make certain sacrifices for my career as some other people may do. Make sense? But ofcourse, medicine is still an amazing career.

So any advice? Should I take up my offer this year or should I not compromise my dream career and try once more?