Feeling down

Just needed some encouragement today. 13 dpo on cycle 15 and got a bfn. Pretty sure I'm out again this month 😫 I'm just so mentally tired. I tried on my own for a 14 months. Beginning of last month I asked my dr for assistance she put me on a fertility diet and metformin. I usually use opks strips but this month I bought digital opks and used preseed. Got a positive opk on the 22nd so I bd for the next three nights. I'm doing everything I can and it just isn't working. My dr wants to see me in May and if it hasn't happened by then she will prescribe me clomid as well. Just don't think mentally I can do 3 more months of disappointment 😢